diff --git a/aggregator.py b/aggregator.py
index 3ae8db4..8baec73 100644
--- a/aggregator.py
+++ b/aggregator.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 from functools import partial
-import postprocessor
+import snapshotprocessor
 
 try:
     from mpi4py.futures import MPIPoolExecutor
@@ -14,44 +14,44 @@ except ModuleNotFoundError:
     mpi = False
 
 
-def _map_aux(fun, path, path_out, pp_params, run_num, **kwargs):
+def _map_aux(fun, path, path_out, params, run_num, **kwargs):
     try:
-        pp = postprocessor.PostProcessor(
-            path + "/" + run_num[0], run_num[1], path_out + "/" + run_num[0], pp_params
+        snap = snapshotprocessor.SnapshotProcessor(
+            path + "/" + run_num[0], run_num[1], path_out + "/" + run_num[0], params
         )
     except Exception as e:
         print(e)
         raise
-    return fun(pp, **kwargs)
+    return fun(snap, **kwargs)
 
 
-def _map_rule(pp, rule, arg, overwrite, overwrite_dep):
-    return pp.process(rule, arg, overwrite, overwrite_dep)
+def _map_rule(snap, rule, arg, overwrite, overwrite_dep):
+    return snap.process(rule, arg, overwrite, overwrite_dep)
 
 
 class Aggregator:
-    def get_pp_list(self, select=None):
+    def get_snap_list(self, select=None):
 
         if select is not None:
             runs, nums = self.selector.select(**select)
         else:
             runs = self.runs
             nums = self.nums
-        return [self.pp[run][num] for run in runs for num in nums[run]]
+        return [self.snaps[run][num] for run in runs for num in nums[run]]
 
     def map(self, func, select=None, num_process=None, **kwargs):
 
-        pp_list = self.get_pp_list(select)
+        snaps = self.get_snap_list(select)
 
         if num_process is None:
-            num_process = self.pp_params.process.num_process
+            num_process = self.params.process.num_process
 
         if num_process == 1:
-            result = [func(pp, **kwargs) for pp in pp_list]
+            result = [func(snap, **kwargs) for snap in snaps]
         else:
-            run_num = [(pp.run, pp.num) for pp in pp_list]
+            run_num = [(snap.run, snap.num) for snap in snaps]
             map_fn = partial(
-                _map_aux, func, self.path, self.path_out, self.pp_params, **kwargs
+                _map_aux, func, self.path, self.path_out, self.params, **kwargs
             )
             if mpi:
                 executor = MPIPoolExecutor(max_workers=num_process)
diff --git a/baseprocessor.py b/baseprocessor.py
index 9f8b8b1..25522c5 100644
--- a/baseprocessor.py
+++ b/baseprocessor.py
@@ -11,7 +11,7 @@ import numpy as np
 import tables
 
 from tables import HDF5ExtError
-from pp_params import default_params, load_params
+from params import default_params, load_params
 from units import U
 
 
@@ -52,16 +52,16 @@ class BaseProcessor:
     rules = {}
     solve_self_dep = True
 
-    def __init__(self, path, path_out=None, pp_params=None, tag=None):
-        if pp_params is None:
-            self.pp_params = default_params()
-        elif type(pp_params) == str:
-            self.pp_params = load_params(pp_params)
+    def __init__(self, path, path_out=None, params=None, tag=None):
+        if params is None:
+            self.params = default_params()
+        elif type(params) == str:
+            self.params = load_params(params)
         else:
-            self.pp_params = copy.deepcopy(pp_params)
+            self.params = copy.deepcopy(params)
 
         if tag is not None:
-            self.pp_params.out.tag = tag
+            self.params.out.tag = tag
 
         # Determining output directory
         if path_out is None:
@@ -70,7 +70,7 @@ class BaseProcessor:
             self.path_out = path_out
 
     def _log(self, string, status=""):
-        if self.pp_params.process.verbose:
+        if self.params.process.verbose:
             if len(status) > 0:
                 print(status + ": " + self.log_id + string)
             else:
diff --git a/fragdisk_galactica.py b/fragdisk_galactica.py
index 946c038..1848e9f 100644
--- a/fragdisk_galactica.py
+++ b/fragdisk_galactica.py
@@ -14,7 +14,7 @@ from astrophysix.simdm.datafiles import PlotInfo, PlotType
 from astrophysix.utils.file import FileType
 
 from plotter import Plotter
-from pp_params import default_params
+from params import default_params
 from ramses_astrophysix import ramses
 
 
@@ -32,18 +32,18 @@ select = {
 }
 
 
-pp_params = default_params()
-pp_params.input.nml_filename = "disk.nml"
-pp_params.pymses.map_size = 2048
-pp_params.pymses.zoom = 4
-pp_params.pymses.filter = False
-pp_params.pymses.variables = ["rho", "vel", "P", "g"]
-pp_params.pymses.multiprocessing = True
-pp_params.process.verbose = True
-pp_params.disk.enable = True
-pp_params.disk.nb_bin = 100
-pp_params.pdf.nb_bin = 100
-pp_params.process.num_process = 10
+params = default_params()
+params.input.nml_filename = "disk.nml"
+params.pymses.map_size = 2048
+params.pymses.zoom = 4
+params.pymses.filter = False
+params.pymses.variables = ["rho", "vel", "P", "g"]
+params.pymses.multiprocessing = True
+params.process.verbose = True
+params.disk.enable = True
+params.disk.nb_bin = 100
+params.pdf.nb_bin = 100
+params.process.num_process = 10
 in_dir = "/drf/projets/alfven-data/nbrucy/simus/fragdisk"
 out_dir = "/dsm/anais/storageA/nbrucy/visus/fragdisk/mnras"
 in_dir_conv = "/drf/projets/alfven-data/nbrucy/simus/conv_disk"
@@ -166,7 +166,7 @@ pl_units = Plotter(
     filter_name="104_beta4_jr13",
     in_nums="last",
     path_out=out_dir,
-    pp_params=pp_params,
+    params=params,
 )
 info = pl_units.comp.info
 rd = U.Unit.create_unit(
@@ -223,8 +223,8 @@ for group in groups:
     if group == "jr13_tic":
         # JR13_TIC
 
-        pp_params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.8}"
-        pp_params.astrophysix.descr_fmt = """
+        params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.8}"
+        params.astrophysix.descr_fmt = """
         <p>Group {tag:.8}, $\\beta$ = {nml[cloud_params/beta_cool]}.</p>
         """
 
@@ -236,14 +236,14 @@ for group in groups:
             sort_run_by=nml_key,
             path_out=out_dir,
             tag="jr13_tic_mnras",
-            pp_params=pp_params,
+            params=params,
             unit_time=orp,
         )
 
     if group == "jr12_tic":
         # JR12_TIC
-        pp_params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.8}"
-        pp_params.astrophysix.descr_fmt = """
+        params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.8}"
+        params.astrophysix.descr_fmt = """
         <p>Group {tag:.8}, $\\beta$ = {nml[cloud_params/beta_cool]}.</p>
         """
         runs_12 = "0[0-9][0-9]_beta*_jr12"
@@ -255,14 +255,14 @@ for group in groups:
             filter_nml=("cloud_params", "!=", 7),
             path_out=out_dir,
             tag="jr12_tic_mnras",
-            pp_params=pp_params,
+            params=params,
             unit_time=orp,
         )
 
     if group == "jr12":
 
-        pp_params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.4}"
-        pp_params.astrophysix.descr_fmt = """
+        params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.4}"
+        params.astrophysix.descr_fmt = """
         <p>Group {tag:.4}, $\\beta$ = {nml[cloud_params/beta_cool]}</p>
         """
 
@@ -275,14 +275,14 @@ for group in groups:
             sort_run_by=nml_key,
             path_out=out_dir,
             tag="jr12_mnras",
-            pp_params=pp_params,
+            params=params,
             unit_time=orp,
         )
 
     if group == "jr11":
 
-        pp_params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.4}"
-        pp_params.astrophysix.descr_fmt = """
+        params.astrophysix.simu_fmt = "beta{nml[cloud_params/beta_cool]:g}_{tag:.4}"
+        params.astrophysix.descr_fmt = """
         <p>Group {tag:.4}, $\\beta$ = {nml[cloud_params/beta_cool]}</p>
         """
 
@@ -295,7 +295,7 @@ for group in groups:
             filter_nml=("cloud_params/beta_cool", ">", 3),
             path_out=out_dir_conv,
             tag="jr11_mnras",
-            pp_params=pp_params,
+            params=params,
             unit_time=orp,
         )
 
@@ -305,8 +305,8 @@ for group in groups:
 # -------------------------------------------------------------------------------------------------------------------- #
 
 for pl in pls:
-    pl.pp_params.process.verbose = True
-    pl.comp.pp_params.process.verbose = True
+    pl.params.process.verbose = True
+    pl.comp.params.process.verbose = True
     for run in pl.runs:
         simu = pl.simulations[run]
         proj.simulations.add(simu)
diff --git a/galaxy.py b/galaxy.py
index a40ad4d..6135ac3 100644
--- a/galaxy.py
+++ b/galaxy.py
@@ -98,8 +98,8 @@ def get_coldens(pp):
 
     im_extent = np.array(pp.get_attribute("/maps", "im_extent"))
     im_extent *= pp.info["unit_length"].express(U.kpc)
-    map_size = pp.pp_params.pymses.map_size
-    center = np.array(pp.pp_params.disk.center)
+    map_size = pp.params.pymses.map_size
+    center = np.array(pp.params.disk.center)
     center *= pp.info["unit_length"].express(U.kpc)
 
     # Physical size of cells
diff --git a/gui.py b/gui.py
index 123561f..6561773 100644
--- a/gui.py
+++ b/gui.py
@@ -1,4 +1,6 @@
 import matplotlib as mpl
+import numpy as np
+from functools import partial
 import matplotlib.patches as patches
 import matplotlib.pyplot as plt
 from matplotlib.lines import Line2D
@@ -8,14 +10,14 @@ from matplotlib.widgets import (
     CheckButtons,
     LassoSelector,
     PolygonSelector,
-    RadioButtons,
     Slider,
     SpanSelector,
 )
 from scipy.stats import linregress
 from skimage.draw import line
 
-from postprocessor import *
+from snapshotprocessor import SnapshotProcessor
+from params import default_params
 
 
 class DraggablePoint:
@@ -184,42 +186,6 @@ class DraggableLine:
         self.list_points[1].line.remove()
 
 
-class FitterTool:
-    """
-    Flexible fitter tool
-    """
-
-    def __init__(self, ax, bounds=None):
-        self.ax = ax
-        self.bounds = bounds
-        self.bounds_selector = SpanSelector(
-            self.ax, self.onselect, "horizontal", useblit=True, span_stays=True
-        )
-        self.fitline = DraggableLine(self, self.ax_gamma, [0, 0], [1, 0.3], 0.05)
-
-        if update_map and self.gamma_3d_button.get_status()[1]:
-            lr = linregress(rho[rho > -4], cs[rho > -4])
-            (a, b, r, _, _) = lr
-            self.line_gamma.clear()
-            del self.line_gamma
-            rhomin, rhomax = np.min(rho), np.max(rho)
-            self.line_gamma = DraggableLine(
-                self,
-                self.ax_gamma,
-                [rhomin, a * rhomin + b],
-                [rhomax, a * rhomax + b],
-                0.05,
-            )
-            print("Gamma linregress : {}".format(lr))
-        else:
-            lps = self.line_gamma.list_points
-            xa, ya, xb, yb = lps[0].x, lps[0].y, lps[1].x, lps[1].y
-            a = (yb - ya) / (xb - xa)
-
-    def onselect(self, vmin, vmax):
-        self.bounds = (vmin, vmax)
-
-
 class InteractiveGUI:
     """
     This is a matplotlib interactive session to restrain analysis to a specific area
@@ -245,7 +211,7 @@ class InteractiveGUI:
             self.fcs = np.copy(self.fcs_map)
             self.fmap[np.logical_not(self.mask)] = np.nan
 
-            ## Map
+            # Map
             plt.sca(self.ax_fluct)
             if first:
                 self.im = plt.imshow(
@@ -262,7 +228,7 @@ class InteractiveGUI:
             else:
                 self.im.set_data(self.fmap)
 
-            ## Gamma
+            # Gamma
             plt.sca(self.ax_gamma)
 
             if self.gamma_3d_button.get_status()[0]:
@@ -317,7 +283,7 @@ class InteractiveGUI:
 
         self.ax_gamma.set_title("$\Gamma$ = {:.3g}".format(self.get_gamma(a)))
 
-        ## PDF
+        # PDF
         if first or update_map:
             plt.sca(self.ax_pdf)
             nb_cells = np.sum(self.mask_flat)
@@ -325,7 +291,7 @@ class InteractiveGUI:
                 self.std_nb_cells = nb_cells
                 values, self.edges = np.histogram(
                     np.log10(self.fmap.flatten()[self.mask_flat]),
-                    self.pp.pp_params.pdf.nb_bin,
+                    self.pp.params.pdf.nb_bin,
                     weights=np.ones(nb_cells) / self.std_nb_cells,
                 )
                 edges = self.edges
@@ -340,8 +306,8 @@ class InteractiveGUI:
 
             centers = 0.5 * (edges[1:] + edges[:-1])
             mask_fit = (
-                (centers > self.pp.pp_params.pdf.xmin_fit)
-                & (centers < self.pp.pp_params.pdf.xmax_fit)
+                (centers > self.pp.params.pdf.xmin_fit)
+                & (centers < self.pp.params.pdf.xmax_fit)
                 & (values > 0)
             )
             (a, b, r, _, _) = linregress(centers[mask_fit], np.log10(values[mask_fit]))
@@ -364,21 +330,21 @@ class InteractiveGUI:
                 self.fit.set_label(r"a = {:.3g}, $R^2$ = {:.3g}".format(a, r ** 2))
             plt.legend()
 
-        ### PROFILE
+        # PROFILE
         plt.sca(self.ax_profile)
         lps = self.line_profile.list_points
         xa, ya, xb, yb = lps[0].x, lps[0].y, lps[1].x, lps[1].y
         coor_pix = list(
             np.asarray(
-                (np.array([xa, ya, xb, yb]) * self.pp.pp_params.pymses.zoom + 0.5)
+                (np.array([xa, ya, xb, yb]) * self.pp.params.pymses.zoom + 0.5)
                 * self.shape[0],
                 dtype=int,
             )
         )
         xpp, ypp = line(*coor_pix)
         rho_prof = self.rho_map[ypp, xpp]
-        xp = ((xpp / float(self.shape[0])) - 0.5) / self.pp.pp_params.pymses.zoom
-        yp = ((ypp / float(self.shape[1])) - 0.5) / self.pp.pp_params.pymses.zoom
+        xp = ((xpp / float(self.shape[0])) - 0.5) / self.pp.params.pymses.zoom
+        yp = ((ypp / float(self.shape[1])) - 0.5) / self.pp.params.pymses.zoom
         print(xp, yp, xpp, ypp)
         x = np.sqrt(np.abs((xp - xa) * (xb - xa) + (yp - ya) * (yb - ya)))
         x = x - float(x[0])
@@ -482,27 +448,27 @@ class InteractiveGUI:
         self.fit_prof_vmax = vmax
         self.draw()
 
-    def __init__(self, num, path="./", pp_params=None, datamap_key="fluct_coldens_z"):
+    def __init__(self, num, path="./", params=None, datamap_key="fluct_coldens_z"):
         """
         Interactive plotting
 
         """
-        if pp_params is None:
-            pp_params = default_params()
-            pp_params.input.nml_filename = "disk.nml"
-            pp_params.out.interactive = True
-            pp_params.pymses.map_size = 4096
-            pp_params.pymses.zoom = 4
+        if params is None:
+            params = default_params()
+            params.input.nml_filename = "disk.nml"
+            params.out.interactive = True
+            params.pymses.map_size = 4096
+            params.pymses.zoom = 4
 
-            pp_params.pymses.variables = ["rho", "vel", "P"]
+            params.pymses.variables = ["rho", "vel", "P"]
 
-            pp_params.disk.enable = True
-            pp_params.disk.nb_bin = 200
-            pp_params.pdf.nb_bin = 100
+            params.disk.enable = True
+            params.disk.nb_bin = 200
+            params.pdf.nb_bin = 100
 
         self.fig = plt.figure(figsize=(10, 8))
 
-        self.pp = PostProcessor(path, num, pp_params=pp_params, tag="interactive")
+        self.pp = SnapshotProcessor(path, num, params=params, tag="interactive")
         self.pp.pdf_coldens("z")
         self.pp.pdf_rho("z")
         self.pp.pdf_T("z")
@@ -523,8 +489,8 @@ class InteractiveGUI:
         self.rr = np.sqrt(self.xx ** 2 + self.yy ** 2)
         self.rhocs = np.column_stack((self.frho_map.flatten(), self.fcs_map.flatten()))
 
-        self.rmin = self.pp.pp_params.disk.rmin_pdf / 2.0
-        self.rmax = self.pp.pp_params.disk.rmax_pdf / 2.0
+        self.rmin = self.pp.params.disk.rmin_pdf / 2.0
+        self.rmax = self.pp.params.disk.rmax_pdf / 2.0
         self.mask = (self.rr >= self.rmin) & (self.rr <= self.rmax)
         self.mask_flat = self.mask.flatten()
 
@@ -553,11 +519,11 @@ class InteractiveGUI:
 
         ax_rmax = plt.axes([0.05, 0.07, 0.15, 0.02])
         self.srmax = Slider(
-            ax_rmax, r"$r_{max}$", 0, 0.7 / pp_params.pymses.zoom, valinit=self.rmax
+            ax_rmax, r"$r_{max}$", 0, 0.7 / params.pymses.zoom, valinit=self.rmax
         )
         ax_rmin = plt.axes([0.05, 0.03, 0.15, 0.02])
         self.srmin = Slider(
-            ax_rmin, r"$r_{min}$", 0, 0.7 / pp_params.pymses.zoom, valinit=self.rmin
+            ax_rmin, r"$r_{min}$", 0, 0.7 / params.pymses.zoom, valinit=self.rmin
         )
         ax_lasso = plt.axes([0.6, 0.07, 0.19, 0.02])
         ax_poly = plt.axes([0.8, 0.07, 0.19, 0.02])
diff --git a/ism.py b/ism.py
index f513474..bfa6c31 100644
--- a/ism.py
+++ b/ism.py
@@ -3,7 +3,7 @@
 import numpy as np
 import pandas as pd
 from plotter import U
-import postprocessor
+import snapshotprocessor
 
 mp = 1.4 * 1.66 * 10 ** (-24) * U.g
 z0 = 150 * U.pc
@@ -53,7 +53,7 @@ def get_sinks(pp):
 
 
 def analyze_box(pp):
-    pp.cells["mass"] = postprocessor.mass_func(pp.cells)
+    pp.cells["mass"] = snapshotprocessor.mass_func(pp.cells)
     pp.coldens("z")
     coldens = pp.get_value("/maps/coldens_z", unit=U.coldens)
     sinks = get_sinks(pp)
diff --git a/pp_params.py b/params.py
similarity index 93%
rename from pp_params.py
rename to params.py
index 6be735d..0270532 100644
--- a/pp_params.py
+++ b/params.py
@@ -33,4 +33,4 @@ def load_params(filename):
 
 
 def default_params():
-    return load_params(_dir_path + "/pp_params.yml")
+    return load_params(_dir_path + "/params.yml")
diff --git a/pp_params.yml b/params.yml
similarity index 100%
rename from pp_params.yml
rename to params.yml
diff --git a/pipeline.py b/pipeline.py
index 4dd26a1..54d608d 100644
--- a/pipeline.py
+++ b/pipeline.py
@@ -7,11 +7,11 @@ import os
 import numpy as np
 
 from plotter import Plotter, plt
-from postprocessor import PostProcessor, get_time
-from comparator import Comparator
-from pp_params import default_params, load_params
+from snapshotprocessor import SnapshotProcessor, get_time
+from studyprocessor import StudyProcessor
+from params import default_params, load_params
 
-fake_pp = PostProcessor()
+fake_pp = SnapshotProcessor()
 
 parser = argparse.ArgumentParser()
 
@@ -192,23 +192,23 @@ storage_in = args.input_path
 storage_out = args.output_path
 
 if args.config is None:
-    pp_params = default_params()
+    params = default_params()
 else:
-    pp_params = load_params(args.config)
+    params = load_params(args.config)
 
-pp_params.out.zoom = args.zoom
-pp_params.out.tag = args.tag
-pp_params.out.map_size = args.map_size
-pp_params.out.interactive = args.interactive
+params.out.zoom = args.zoom
+params.out.tag = args.tag
+params.out.map_size = args.map_size
+params.out.interactive = args.interactive
 
-pp_params.pymses.fft = args.fft
+params.pymses.fft = args.fft
 
 
-pp_params.disk.on = args.disk
-pp_params.disk.binning = args.binning
-pp_params.disk.nb_bin = args.nb_bin
+params.disk.on = args.disk
+params.disk.binning = args.binning
+params.disk.nb_bin = args.nb_bin
 
-pp_params.pdf.nb_bin = args.pdf_nb_bin
+params.pdf.nb_bin = args.pdf_nb_bin
 
 # extension for out files
 plt.style.use("seaborn-deep")
@@ -265,7 +265,7 @@ for run in runs:
         while not success:
             try:
                 if len(args.process) > 0:
-                    pp = PostProcessor(run, num, pp_params=pp_params)
+                    pp = SnapshotProcessor(run, num, params=params)
                     pp.process(
                         args.process,
                         args.process_args,
@@ -299,7 +299,7 @@ path_in = storage_in + project
 path_out = storage_out + project
 
 if len(args.plot) > 0:
-    pl = Plotter(path_in, runs, nums_success, path_out=path_out, pp_params=pp_params)
+    pl = Plotter(path_in, runs, nums_success, path_out=path_out, params=params)
     pl.process(
         args.plot,
         args.plot_args,
@@ -308,7 +308,7 @@ if len(args.plot) > 0:
     )
 
 if len(args.compare) > 0:
-    cc = Comparator(path_in, runs, nums_success, path_out=path_out, pp_params=pp_params)
+    cc = StudyProcessor(path_in, runs, nums_success, path_out=path_out, params=params)
     cc.process(
         args.compare,
         args.compare_args,
diff --git a/plotter.py b/plotter.py
index 566b7ad..3f5adeb 100644
--- a/plotter.py
+++ b/plotter.py
@@ -30,7 +30,7 @@ import matplotlib.pyplot as plt
 import pspec_read
 from baseprocessor import Rule, BaseProcessor
 from aggregator import Aggregator
-from comparator import Comparator
+from studyprocessor import StudyProcessor
 from run_selector import RunSelector
 from units import U, unit_str, convert_exp
 
@@ -121,7 +121,7 @@ class Plotter(Aggregator, BaseProcessor):
         in_runs=None,
         in_nums=None,
         path_out=None,
-        pp_params=None,
+        params=None,
         selector=None,
         tag=None,
         unit_time=U.year,
@@ -139,19 +139,19 @@ class Plotter(Aggregator, BaseProcessor):
         in_nums : list or dict of the outputs numbers to consider (ex [3, 5]
         or {'run1' : [3, 5], 'run2' : [4, 6])
         path_out : Path where the plot will be saved. By default set to `path`
-        pp_params : Parameters for postprocessing. See pp_params module.
+        params : Parameters for postprocessing. See params module.
         selector : Existing instance of RunSelector, that selects runs and outputs. If set, in_runs and
         in_nums will be ignored
         tag : string to add in the output and data files.
         kwargs : Keyword arguments for RunSelector.
         """
 
-        super(Plotter, self).__init__(path, path_out, pp_params, tag)
+        super(Plotter, self).__init__(path, path_out, params, tag)
 
         # Select runs
         if selector is None:
             self.selector = RunSelector(
-                path, in_runs, in_nums, self.pp_params.input.nml_filename, **kwargs
+                path, in_runs, in_nums, self.params.input.nml_filename, **kwargs
             )
         else:
             self.selector = selector
@@ -161,22 +161,22 @@ class Plotter(Aggregator, BaseProcessor):
         self.runs = self.selector.runs
         self.nums = self.selector.nums
 
-        # Get comparator object
-        self.comp = Comparator(
+        # Get studyprocessor object
+        self.study = StudyProcessor(
             path,
             self.runs,
             self.nums,
             path_out,
-            self.pp_params,
+            self.params,
             unit_time=unit_time,
             selector=self.selector,
         )
 
         # Get postprocesor objets for each run
-        self.pp = self.comp.pp
+        self.snaps = self.study.snaps
 
         # Define log prefix
-        self.log_id = "[plot {}] ".format(self.pp_params.out.tag)
+        self.log_id = "[plot {}] ".format(self.params.out.tag)
 
         # Define rules
         self.def_rules()
@@ -188,12 +188,12 @@ class Plotter(Aggregator, BaseProcessor):
 
     def gen_simus(self):
         self.simulations = {}
-        simu_fmt = self.pp_params.astrophysix.simu_fmt
-        descr_fmt = self.pp_params.astrophysix.descr_fmt
-        tag = self.pp_params.out.tag
+        simu_fmt = self.params.astrophysix.simu_fmt
+        descr_fmt = self.params.astrophysix.descr_fmt
+        tag = self.params.out.tag
         for run in self.runs:
-            pp = self.pp[run][self.nums[run][0]]
-            nml = self.comp.namelist[run]
+            pp = self.snaps[run][self.nums[run][0]]
+            nml = self.study.namelist[run]
             name = simu_fmt.format(run=run, tag=tag, nml=nml)
             exec_time = str(datetime.datetime.fromtimestamp(os.stat(pp.path).st_ctime))
             exec_time = exec_time.split(".")[0]
@@ -210,7 +210,7 @@ class Plotter(Aggregator, BaseProcessor):
             for param in ramses.input_parameters:
                 value = None
                 try:
-                    value = self.comp.get_nml(param.key, run)
+                    value = self.study.get_nml(param.key, run)
                 except KeyError as e:
                     self._log("key {} not found".format(e), "WARNING")
 
@@ -237,8 +237,8 @@ class Plotter(Aggregator, BaseProcessor):
         """
         Check if the dependency belongs to the plotter object or to another one (comp, pp, ..)
         """
-        if dep in self.comp.rules:
-            result = self.comp.process(
+        if dep in self.study.rules:
+            result = self.study.process(
                 dep, dep_arg, overwrite, self.overwrite_dep, select
             )
             if result is not None:
@@ -251,7 +251,7 @@ class Plotter(Aggregator, BaseProcessor):
         Returns true if the plot needs to be redone
         """
         return (
-            self.pp_params.out.interactive
+            self.params.out.interactive
             or overwrite
             or not os.path.exists(plot_filename)
         )
@@ -288,7 +288,7 @@ class Plotter(Aggregator, BaseProcessor):
             name_full = name
 
         # get filetype of the output
-        filetype = filetype_from_ext[self.pp_params.out.ext]
+        filetype = filetype_from_ext[self.params.out.ext]
 
         # Select runs and nums
         if select is not None:
@@ -330,14 +330,14 @@ class Plotter(Aggregator, BaseProcessor):
 
             # Find plot save
             if from_cells or rule.kind == "cells":
-                if not os.path.exists(self.pp[run][num].cells_filename):
+                if not os.exists(self.pp[run][num].cells_filename):
                     self.pp[run][num].load_cells()
                     self.pp[run][num].unload_cells()
                     save = tables.open_file(self.pp[run][num].cells_filename)
             elif rule.kind == "snapshot":
-                save = tables.open_file(self.pp[run][num].filename)
+                save = tables.open_file(self.snaps[run][num].filename)
             else:
-                save = tables.open_file(self.comp.filename, "r")
+                save = tables.open_file(self.study.filename, "r")
 
             # Call plot routine
             try:
@@ -362,7 +362,7 @@ class Plotter(Aggregator, BaseProcessor):
             if plot_info is not None:
                 df.plot_info = plot_info
             if num is not None:
-                snap = self.pp[run][num].snapshot
+                snap = self.snaps[run][num].snapshot
 
                 if overwrite and df.name in snap.datafiles:
                     del snap.datafiles[df.name]
@@ -385,10 +385,10 @@ class Plotter(Aggregator, BaseProcessor):
         if self._needs_computation(overwrite, plot_filename):
             plot_info = rule.plot(save, arg, **kwargs)
 
-            if not self.pp_params.out.interactive and close:
+            if not self.params.out.interactive and close:
                 plt.tight_layout(pad=1)
 
-            if self.pp_params.out.save:
+            if self.params.out.save:
                 plt.savefig(plot_filename)
                 self._log("{} plotted".format(plot_filename), "SUCCESS")
             else:
@@ -396,7 +396,7 @@ class Plotter(Aggregator, BaseProcessor):
                     "{} plotted".format(os.path.basename(plot_filename)), "SUCCESS"
                 )
 
-            if not self.pp_params.out.interactive and close:
+            if not self.params.out.interactive and close:
                 plt.close()
             return plot_info
         else:
@@ -406,10 +406,10 @@ class Plotter(Aggregator, BaseProcessor):
         """
         Determine a filename based on rule name, run, output and parameters
         """
-        tag_name = self.pp_params.out.tag
+        tag_name = self.params.out.tag
 
-        if fmt is None and self.pp_params.out.fmt == "":
-            if not self.pp_params.out.tag == "":
+        if fmt is None and self.params.out.fmt == "":
+            if not self.params.out.tag == "":
                 tag_name = "_" + tag_name
 
             if run is not None and num is not None:
@@ -419,11 +419,11 @@ class Plotter(Aggregator, BaseProcessor):
             else:
                 fmt = "{out}/{name}{tag}{ext}"
         elif fmt is None:
-            fmt = self.pp_params.out.fmt
+            fmt = self.params.out.fmt
 
         nml = None
         if run is not None:
-            nml = self.comp.namelist[run]
+            nml = self.study.namelist[run]
 
         return fmt.format(
             run=run,
@@ -432,7 +432,7 @@ class Plotter(Aggregator, BaseProcessor):
             num=num,
             nml=nml,
             out=self.path_out,
-            ext=self.pp_params.out.ext,
+            ext=self.params.out.ext,
         )
 
     def get_label_run(self, run, label=None, nml_key=None, time=None):
@@ -514,11 +514,9 @@ class Plotter(Aggregator, BaseProcessor):
         title = self.get_label_run(run, title, nml_key)
 
         if put_time:
-            time = self.save.root._v_attrs.time * self.comp.info["unit_time"]
+            time = self.save.root._v_attrs.time * self.study.info["unit_time"]
             u_str = unit_str(unit_time, format="{unit}")
-            time_str = self.pp_params.plot.time_fmt.format(
-                time.express(unit_time), u_str
-            )
+            time_str = self.params.plot.time_fmt.format(time.express(unit_time), u_str)
             if len(title) > 0:
                 title = title + " | " + time_str
             else:
@@ -593,7 +591,7 @@ class Plotter(Aggregator, BaseProcessor):
             dmap, extent=im_extent, origin="lower", norm=norm, cmap=cmap, **kwargs
         )
 
-        plt.locator_params(axis="both", nbins=self.pp_params.plot.ntick)
+        plt.locator_params(axis="both", nbins=self.params.plot.ntick)
 
         if xlabel is None:
             xlabel = self._ax_title[ax_h]
@@ -781,7 +779,7 @@ class Plotter(Aggregator, BaseProcessor):
 
         label, unit_old, unit = self._ax_label_unit(dmap_vh_node, "", unit, unit_coeff)
 
-        vel_red = self.pp_params.plot.vel_red
+        vel_red = self.params.plot.vel_red
 
         # take only a subset of velocities
         map_vh_red = dmap_vh[::vel_red, ::vel_red] * unit_old.express(unit)
@@ -835,7 +833,7 @@ class Plotter(Aggregator, BaseProcessor):
 
         # TODO : redo this with im_extent
 
-        vel_red = self.pp_params.plot.vel_red
+        vel_red = self.params.plot.vel_red
         radius = self.save.root.maps._v_attrs.radius
         center = self.save.root.maps._v_attrs.center
         lbox = self.save.root._v_attrs.lbox
@@ -923,7 +921,7 @@ class Plotter(Aggregator, BaseProcessor):
             if nml_color is None:
                 color = colors[run]
             else:
-                nml = self.comp.get_nml(nml_color, run)
+                nml = self.study.get_nml(nml_color, run)
                 try:
                     color = colors[nml]
                 except TypeError:
@@ -1043,8 +1041,8 @@ class Plotter(Aggregator, BaseProcessor):
 
         # If relevent, get time
         if put_time:
-            time = self.save.root._v_attrs.time * self.comp.info["unit_time"]
-            time_str = self.pp_params.plot.time_fmt.format(
+            time = self.save.root._v_attrs.time * self.study.info["unit_time"]
+            time_str = self.params.plot.time_fmt.format(
                 time.express(unit_time), unit_time.latex.replace("text", "math")
             )
             time_str = f"${time_str}$"
@@ -1125,11 +1123,11 @@ class Plotter(Aggregator, BaseProcessor):
                 color = colors[run]
             elif nml_color == "time":
                 time = (
-                    self.save.root._v_attrs.time * self.comp.info["unit_time"]
+                    self.save.root._v_attrs.time * self.study.info["unit_time"]
                 ).express(unit_time)
                 color = colors(time)
             else:
-                nml = self.comp.get_nml(nml_color, run)
+                nml = self.study.get_nml(nml_color, run)
                 try:
                     color = colors[nml]
                 except TypeError:
@@ -1254,7 +1252,7 @@ class Plotter(Aggregator, BaseProcessor):
         ssfr_sun = 2.5e-9
         ssfr_ken = ssfr_sun * n0 ** 1.4
 
-        coeff = ssfr_ken * 1e6 * (self.comp.info["unit_length"].express(U.pc)) ** 2
+        coeff = ssfr_ken * 1e6 * (self.study.info["unit_length"].express(U.pc)) ** 2
         for i in np.arange(tmin, max(tmax, tmin + ymax / coeff), step):
             t = np.linspace(0, tmax, 1000)
             plt.plot(t + i, t * coeff, ls="--", lw=0.9, color="grey")
@@ -1661,7 +1659,7 @@ class Plotter(Aggregator, BaseProcessor):
         ]
 
         # Generic rules directly from Ramses fields
-        for field in self.pp_params.pymses.variables:
+        for field in self.params.pymses.variables:
 
             def generic_rule(name):
 
diff --git a/postprocessor.py b/snapshotprocessor.py
similarity index 93%
rename from postprocessor.py
rename to snapshotprocessor.py
index 3472017..dfe24f9 100644
--- a/postprocessor.py
+++ b/snapshotprocessor.py
@@ -42,8 +42,7 @@ from baseprocessor import (
     oct_vect_getter,
 )
 
-from run_selector import NamelistRecursive
-import f90nml
+from run_selector import RunSelector
 
 
 # Getters
@@ -255,7 +254,8 @@ def degrade_map(dmap, nnew, integrate=False):
     return dmap_new
 
 
-class PostProcessor(HDF5Container):
+class SnapshotProcessor(HDF5Container):
+
     """
     This class enable to compute and save derived quantities from the raw output
     """
@@ -286,19 +286,29 @@ class PostProcessor(HDF5Container):
         path=None,
         num=None,
         path_out=None,
-        pp_params=None,
+        params=None,
         tag=None,
+        selector=None,
         unit_time=U.year,
     ):
         """
         Creates the basic structures needed for the outputs
+
+        Parameters
+        ----------
+        path : str, path of where the outputs are located
+        path_out : str, where to store postprocessings results
+        params : str or params instance
+        tag : str, distinguish this postprocessing set
+        selector : RunSelector instance
+        unit_time : Unit instance, used for astrophysix
         """
 
-        super(PostProcessor, self).__init__(path, path_out, pp_params, tag)
+        super(SnapshotProcessor, self).__init__(path, path_out, params, tag)
 
         # Open outfile
-        if not self.pp_params.out.tag == "":
-            tag_name = self.pp_params.out.tag + "_"
+        if not self.params.out.tag == "":
+            tag_name = self.params.out.tag + "_"
         else:
             tag_name = ""
 
@@ -325,113 +335,34 @@ class PostProcessor(HDF5Container):
         if not os.path.exists(self.path_out):
             os.makedirs(self.path_out)
 
-        self.open()
-
-        # Ramses Output
         self.path = path
         self.run = os.path.basename(path)
         self.num = num
-        self._ro = pymses.RamsesOutput(
-            path,
-            num,
-            order=self.pp_params.pymses.order,
-            verbose=self.pp_params.pymses.verbose,
-        )
-        self._amr = self._ro.amr_source(self.pp_params.pymses.variables)
-        self._part = self._ro.particle_source(self.pp_params.pymses.part_variables)
 
-        if self.pp_params.pymses.filter:
-            self.min_coords = np.array(self.pp_params.pymses.min_coords)
-            self.max_coords = np.array(self.pp_params.pymses.max_coords)
-            box = reg.Box((self.min_coords, self.max_coords))
-
-            amr_filt = RegionFilter(box, self._amr)
-            self._amr = amr_filt
-            part_filt = RegionFilter(box, self._part)
-            self._part = part_filt
-
-        self.info = self._ro.info.copy()
-
-        # Density operator
-        self._rho_op = ScalarOperator(
-            lambda dset: dset["rho"], self._ro.info["unit_density"]
-        )
-
-        # Density ray tracer
-        if self.pp_params.pymses.fft:
-            self._rt = splatting.SplatterProcessor(
-                self._amr, self._ro.info, self._rho_op
+        # Create selector object
+        if selector is None:
+            selector = RunSelector(
+                os.path.dirname(path),
+                self.run,
+                self.num,
+                self.params.input.nml_filename,
             )
-        else:
-            self._rt = raytracing.RayTracer(self._amr, self._ro.info, self._rho_op)
 
-        if not self.pp_params.pymses.multiprocessing:
-            self._rt.disable_multiprocessing()
-
-        # Set the extent of the image
-        self._radius = 0.5 / self.pp_params.pymses.zoom
+        self.info = selector.info[self.run][self.num]
+        self.namelist = selector.namelist[self.run][self.num]
         self.lbox = self.info["boxlen"]
 
-        if self.pp_params.pymses.filter:
-            center = (self.max_coords + self.min_coords) / 2.0
-            im_extent = np.array(
-                [
-                    self.min_coords[0],
-                    self.max_coords[0],
-                    self.min_coords[1],
-                    self.max_coords[1],
-                ]
-            )
-            distance = (self.max_coords[2] - self.min_coords[2]) / 2.0
-        else:
-            center = self.pp_params.pymses.center
-            im_extent = np.array(
-                [
-                    (-self._radius + center[0]),
-                    (self._radius + center[0]),
-                    (-self._radius + center[1]),
-                    (self._radius + center[1]),
-                ]
-            )
-            distance = self._radius
-
         # Get time
-        self.time = self._ro.info["time"]
-
-        # Get namelist
-        self.namelist = None
-        path_nml = path + "/" + self.pp_params.input.nml_filename
-        self.namelist = NamelistRecursive(f90nml.read(path_nml))
+        self.time = self.info["time"]
 
         # Set post processing attributes
+        self.open()
         self.save.root._v_attrs.dir = os.path.dirname(path)
         self.save.root._v_attrs.run = os.path.basename(path)
         self.save.root._v_attrs.num = num
         self.save.root._v_attrs.lbox = self.lbox
         self.save.root._v_attrs.unit_length = self.info["unit_length"]
         self.save.root._v_attrs.time = self.time
-
-        if "/maps" not in self.save:
-            self.save.create_group("/", "maps", "2D maps")
-        self.save.root.maps._v_attrs.center = center
-        self.save.root.maps._v_attrs.radius = self._radius
-        self.save.root.maps._v_attrs.im_extent = im_extent
-
-        # Initialize cameras
-        self._cam = {}
-        for ax_los in self._ax_nb:  # los = line of sight
-            ax_v = self._axes_v[ax_los]
-
-            self._cam[ax_los] = Camera(
-                center=self.pp_params.pymses.center,
-                line_of_sight_axis=ax_los,
-                region_size=[im_extent[1] - im_extent[0], im_extent[3] - im_extent[2]],
-                distance=distance,
-                far_cut_depth=distance,
-                up_vector=ax_v,
-                map_max_size=self.pp_params.pymses.map_size,
-            )
-
         self.close()
 
         self.log_id = "[{}, {}] ".format(self.run, self.num)
@@ -451,8 +382,97 @@ class PostProcessor(HDF5Container):
             data_reference="OUTPUT_{}".format(self.num),
         )
 
+        try:
+            self.init_pymses()
+        except FileNotFoundError:
+            self._log("Pymses not initialized", "WARNING")
+
         self.def_rules()
 
+    def init_pymses(self):
+        self._ro = pymses.RamsesOutput(
+            self.path,
+            self.num,
+            order=self.params.pymses.order,
+            verbose=self.params.pymses.verbose,
+        )
+        self._amr = self._ro.amr_source(self.params.pymses.variables)
+        self._part = self._ro.particle_source(self.params.pymses.part_variables)
+
+        if self.params.pymses.filter:
+            self.min_coords = np.array(self.params.pymses.min_coords)
+            self.max_coords = np.array(self.params.pymses.max_coords)
+            box = reg.Box((self.min_coords, self.max_coords))
+
+            amr_filt = RegionFilter(box, self._amr)
+            self._amr = amr_filt
+            part_filt = RegionFilter(box, self._part)
+            self._part = part_filt
+
+        # Density operator
+        self._rho_op = ScalarOperator(
+            lambda dset: dset["rho"], self._ro.info["unit_density"]
+        )
+
+        # Density ray tracer
+        if self.params.pymses.fft:
+            self._rt = splatting.SplatterProcessor(
+                self._amr, self._ro.info, self._rho_op
+            )
+        else:
+            self._rt = raytracing.RayTracer(self._amr, self._ro.info, self._rho_op)
+
+        if not self.params.pymses.multiprocessing:
+            self._rt.disable_multiprocessing()
+
+        # Set the extent of the image
+        self._radius = 0.5 / self.params.pymses.zoom
+        if self.params.pymses.filter:
+            center = (self.max_coords + self.min_coords) / 2.0
+            im_extent = np.array(
+                [
+                    self.min_coords[0],
+                    self.max_coords[0],
+                    self.min_coords[1],
+                    self.max_coords[1],
+                ]
+            )
+            distance = (self.max_coords[2] - self.min_coords[2]) / 2.0
+        else:
+            center = self.params.pymses.center
+            im_extent = np.array(
+                [
+                    (-self._radius + center[0]),
+                    (self._radius + center[0]),
+                    (-self._radius + center[1]),
+                    (self._radius + center[1]),
+                ]
+            )
+            distance = self._radius
+
+        # Initialize cameras
+        self._cam = {}
+        for ax_los in self._ax_nb:  # los = line of sight
+            ax_v = self._axes_v[ax_los]
+
+            self._cam[ax_los] = Camera(
+                center=self.params.pymses.center,
+                line_of_sight_axis=ax_los,
+                region_size=[im_extent[1] - im_extent[0], im_extent[3] - im_extent[2]],
+                distance=distance,
+                far_cut_depth=distance,
+                up_vector=ax_v,
+                map_max_size=self.params.pymses.map_size,
+            )
+
+        self.open()
+        if "/maps" not in self.save:
+            self.save.create_group("/", "maps", "2D maps")
+        self.save.root.maps._v_attrs.center = center
+        self.save.root.maps._v_attrs.radius = self._radius
+        self.save.root.maps._v_attrs.im_extent = im_extent
+        self.close()
+
     def load_data(self, points_src, filename, save, keys=None):
         """
         Load data from the source file in the memory.
@@ -496,7 +516,7 @@ class PostProcessor(HDF5Container):
             self.parts = self.load_data(
                 self._part,
                 self.parts_filename,
-                self.pp_params.process.save_parts,
+                self.params.process.save_parts,
                 keys=keys,
             )
             self.parts_loaded = True
@@ -521,7 +541,7 @@ class PostProcessor(HDF5Container):
             self.cells = self.load_data(
                 cells_src,
                 self.cells_filename,
-                self.pp_params.process.save_cells,
+                self.params.process.save_cells,
                 keys=keys,
             )
             self.cells_loaded = True
@@ -551,7 +571,7 @@ class PostProcessor(HDF5Container):
             pos = dset.points
         except AttributeError:
             pos = dset["pos"]
-        pos = pos - np.array(self.pp_params.disk.center)
+        pos = pos - np.array(self.params.disk.center)
         return pos
 
     def getter_vect_r(self, dset, name_vect):
@@ -576,7 +596,7 @@ class PostProcessor(HDF5Container):
         Returns the position in normalized units centered on the position of the star
         """
         pos = dset.get_cell_centers()
-        pos = pos - np.array(self.pp_params.disk.center)
+        pos = pos - np.array(self.params.disk.center)
         return pos
 
     def oct_getter_vect_r(self, dset, name_vect):
@@ -665,12 +685,12 @@ class PostProcessor(HDF5Container):
 
             op = FractionOperator(num, denum, unit)
 
-        if self.pp_params.pymses.fft:
+        if self.params.pymses.fft:
             rt = splatting.SplatterProcessor(self._amr, self._ro.info, op)
         else:
             rt = raytracing.RayTracer(self._amr, self._ro.info, op)
 
-        if not self.pp_params.pymses.multiprocessing:
+        if not self.params.pymses.multiprocessing:
             rt.disable_multiprocessing()
 
         datamap = rt.process(self._cam[ax_los], surf_qty=surf_qty)
@@ -705,7 +725,7 @@ class PostProcessor(HDF5Container):
         else:
             df["value"] = value
 
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
 
         df.sort_values("axis", inplace=True)
@@ -726,7 +746,7 @@ class PostProcessor(HDF5Container):
         else:
             data = np.sum(value, axis=0)
 
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
         return data
 
@@ -744,7 +764,7 @@ class PostProcessor(HDF5Container):
         # Transpose (.T) is for vectorial values
         data = np.sum((weight * value.T).T, axis=0) / np.sum(weight)
 
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
         return data
 
@@ -754,7 +774,7 @@ class PostProcessor(HDF5Container):
         if logbins:
             data = np.log10(data)
         weights = weight_func(self.cells)
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
 
         values, edges = np.histogram(data, bins, weights=weights)
@@ -771,7 +791,7 @@ class PostProcessor(HDF5Container):
 
         centers, B_mean = mean_by_bins(rho, B, bins, logbins)
 
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
         return ({"rho": centers, "B": B_mean}, {"logbins": logbins})
 
@@ -840,7 +860,7 @@ class PostProcessor(HDF5Container):
         else:
             centers = 0.5 * (rho_bins[1:] + rho_bins[:-1])
 
-        if self.pp_params.process.unload_cells:
+        if self.params.process.unload_cells:
             self.unload_cells()
         return ({"rho": centers, "Ek_Eb_rho": ek_eb}, {"logbins": logbins})
 
@@ -928,10 +948,10 @@ class PostProcessor(HDF5Container):
         return dmap_P / dmap_rho
 
     def _levels(self, ax_los):
-        self._amr.set_read_levelmax(self.pp_params.pymses.levelmax)
+        self._amr.set_read_levelmax(self.params.pymses.levelmax)
         level_op = MaxLevelOperator()
         rt_level = raytracing.RayTracer(self._amr, self._ro.info, level_op)
-        if not self.pp_params.pymses.multiprocessing:
+        if not self.params.pymses.multiprocessing:
             rt_level.disable_multiprocessing()
         datamap = rt_level.process(self._cam[ax_los], surf_qty=True)
         return datamap.map.T
@@ -978,7 +998,7 @@ class PostProcessor(HDF5Container):
         # Ray tracer for the angular speed
         rt_omega = raytracing.RayTracer(self._amr, self._ro.info, omega_op)
 
-        if not self.pp_params.pymses.multiprocessing:
+        if not self.params.pymses.multiprocessing:
             rt_omega.disable_multiprocessing()
 
         dmap_omega = rt_omega.process(self._cam[ax_los]).map.T
@@ -1020,7 +1040,7 @@ class PostProcessor(HDF5Container):
             # Get coordinates
             im_extent = np.array(self.save.root.maps._v_attrs.im_extent) * space_coeff
 
-            center = np.array(self.pp_params.disk.center) * space_coeff
+            center = np.array(self.params.disk.center) * space_coeff
 
             # Physical size of cells
             dx = (im_extent[1] - im_extent[0]) / map_size
@@ -1046,7 +1066,7 @@ class PostProcessor(HDF5Container):
         """
         Computes radial bins (for disk)
         """
-        center = np.array(self.pp_params.disk.center) * self.lbox
+        center = np.array(self.params.disk.center) * self.lbox
         im_extent = np.array(self.save.root.maps._v_attrs.im_extent) * self.lbox
 
         # radius of the corner of the box plus a margin
@@ -1055,20 +1075,20 @@ class PostProcessor(HDF5Container):
             + 0.1
         )
 
-        bin_in = self.pp_params.disk.bin_in
-        bin_out = self.pp_params.disk.bin_out
-        nb_bin = self.pp_params.disk.nb_bin
+        bin_in = self.params.disk.bin_in
+        bin_out = self.params.disk.bin_out
+        nb_bin = self.params.disk.nb_bin
 
         # radial bins
-        if self.pp_params.disk.binning in ["log", "logarithmic"]:
+        if self.params.disk.binning in ["log", "logarithmic"]:
             lrad_in = np.log10(bin_in)
             lrad_ext = np.log10(bin_out)
             rad_bins = np.logspace(lrad_in, lrad_ext, num=nb_bin)
-        elif self.pp_params.disk.binning in ["lin", "linear"]:
+        elif self.params.disk.binning in ["lin", "linear"]:
             rad_bins = np.linspace(bin_in, bin_out, num=nb_bin)
         else:
             raise RuntimeWarning(
-                f"Invalid parameter {self.pp_params.disk.binning} for disk binning method, using linear binning"
+                f"Invalid parameter {self.params.disk.binning} for disk binning method, using linear binning"
             )
             rad_bins = np.linspace(bin_in, bin_out, num=nb_bin)
 
@@ -1086,8 +1106,8 @@ class PostProcessor(HDF5Container):
         Computes the radius from the center
         """
         im_extent = np.array(self.save.root.maps._v_attrs.im_extent) * self.lbox
-        map_size = self.pp_params.pymses.map_size
-        center = np.array(self.pp_params.disk.center) * self.lbox
+        map_size = self.params.pymses.map_size
+        center = np.array(self.params.disk.center) * self.lbox
 
         # Physical size of cells
         dx = (im_extent[1] - im_extent[0]) / map_size
@@ -1220,15 +1240,15 @@ class PostProcessor(HDF5Container):
         rr = self.get_value("/maps/rr_" + ax_los)
 
         mask_pdf = (
-            (rr > self.pp_params.disk.rmin_pdf)
-            & (rr < self.pp_params.disk.rmax_pdf)
+            (rr > self.params.disk.rmin_pdf)
+            & (rr < self.params.disk.rmax_pdf)
             & (fluct_map > 0)
         )
 
         values, edges = np.histogram(
             np.log10(fluct_map[mask_pdf].flatten()),
-            self.pp_params.pdf.nb_bin,
-            range=self.pp_params.pdf.range,
+            self.params.pdf.nb_bin,
+            range=self.params.pdf.range,
             density=True,
         )
         centers = 0.5 * (edges[1:] + edges[:-1])
@@ -1238,9 +1258,9 @@ class PostProcessor(HDF5Container):
         pdf = self.get_value("/hist/pdf_" + name + "_" + ax_los)
         values, centers = pdf
         mask_fit = (
-            (centers > self.pp_params.pdf.xmin_fit)
-            & (centers < self.pp_params.pdf.xmax_fit)
-            & (values > self.pp_params.pdf.fit_cut * np.max(values))
+            (centers > self.params.pdf.xmin_fit)
+            & (centers < self.params.pdf.xmax_fit)
+            & (values > self.params.pdf.fit_cut * np.max(values))
         )
         (slope, origin, correlation, _, stderr) = linregress(
             centers[mask_fit], np.log10(values[mask_fit])
@@ -1315,7 +1335,7 @@ class PostProcessor(HDF5Container):
         def getter_alpha_grav(dset):
             r2 = np.sum((self.lbox * self.oct_getter_pos_disk(dset)) ** 2, axis=2)
             e2 = (1.0 / 256.0) ** 2
-            gstar = -self.G * self.pp_params.disk.mass_star / (e2 + r2)
+            gstar = -self.G * self.params.disk.mass_star / (e2 + r2)
             gr = self.oct_getter_vect_r(dset, "g") - gstar
             gphi = self.oct_getter_vect_phi(dset, "g")
             return gr * gphi / (4 * np.pi * self.G)
@@ -1388,14 +1408,14 @@ class PostProcessor(HDF5Container):
 
     def _filaments(self):
 
-        datamap_name = self.pp_params.filaments.datamap
-        verbose = self.pp_params.filaments.verbose
-        rmin_frac = self.pp_params.filaments.rmin
-        rmax_frac = self.pp_params.filaments.rmax
-        size_thresh = self.pp_params.filaments.size_thresh
-        skel_thresh = self.pp_params.filaments.skel_thresh
-        branch_thresh = self.pp_params.filaments.branch_thresh
-        glob_thresh = self.pp_params.filaments.glob_thresh
+        datamap_name = self.params.filaments.datamap
+        verbose = self.params.filaments.verbose
+        rmin_frac = self.params.filaments.rmin
+        rmax_frac = self.params.filaments.rmax
+        size_thresh = self.params.filaments.size_thresh
+        skel_thresh = self.params.filaments.skel_thresh
+        branch_thresh = self.params.filaments.branch_thresh
+        glob_thresh = self.params.filaments.glob_thresh
 
         datamap = self.get_value("/maps/" + datamap_name + "_z")
         shape = datamap.shape
@@ -1451,7 +1471,7 @@ class PostProcessor(HDF5Container):
         Compute forces within a filament (for disks), within the slice at z=0
         """
 
-        GM = self.G * self.pp_params.disk.mass_star  # Mass parameter
+        GM = self.G * self.params.disk.mass_star  # Mass parameter
 
         # Find center of filaments
         i_center, j_center = self._filaments_center()
@@ -1465,8 +1485,8 @@ class PostProcessor(HDF5Container):
 
         # Get coordinates
         im_extent = np.array(self.save.root.maps._v_attrs.im_extent) * self.lbox
-        map_size = self.pp_params.pymses.map_size
-        center = np.array(self.pp_params.disk.center) * self.lbox
+        map_size = self.params.pymses.map_size
+        center = np.array(self.params.disk.center) * self.lbox
 
         # Physical size of cells
         dx = (im_extent[1] - im_extent[0]) / map_size
@@ -1661,7 +1681,7 @@ class PostProcessor(HDF5Container):
                 self._filaments,
                 "Filaments",
                 "/datasets",
-                dependencies={self.pp_params.filaments.datamap: "z"},
+                dependencies={self.params.filaments.datamap: "z"},
             ),
             "filaments_forces": Rule(
                 self,
@@ -1837,7 +1857,7 @@ class PostProcessor(HDF5Container):
         ]
 
         # Generic rules directly from Ramses fields
-        for field in self.pp_params.pymses.variables:
+        for field in self.params.pymses.variables:
 
             def generic_rule(name, getter, unit, oct_getter=None):
                 if oct_getter is None:
@@ -2002,7 +2022,7 @@ class PostProcessor(HDF5Container):
 
         self._gen_rule_transform("fluct_coldens", np.nanmax, "max", group="/globals")
 
-        super(PostProcessor, self).def_rules()
+        super(SnapshotProcessor, self).def_rules()
 
 
 def get_time(path, num):
diff --git a/comparator.py b/studyprocessor.py
similarity index 94%
rename from comparator.py
rename to studyprocessor.py
index 05a377c..1f67623 100644
--- a/comparator.py
+++ b/studyprocessor.py
@@ -8,15 +8,15 @@ from scipy.stats import linregress
 
 from baseprocessor import Rule, HDF5Container
 from aggregator import Aggregator
-from postprocessor import PostProcessor
+from snapshotprocessor import SnapshotProcessor
 from run_selector import RunSelector
-from pp_params import default_params
+from params import default_params
 from units import U
 
 
-class Comparator(Aggregator, HDF5Container):
+class StudyProcessor(Aggregator, HDF5Container):
     """
-    Do comparaison between outputs and runs
+    This object is linked to several ramses simulation of a same study
     """
 
     def __init__(
@@ -25,7 +25,7 @@ class Comparator(Aggregator, HDF5Container):
         in_runs,
         in_nums,
         path_out=None,
-        pp_params=default_params(),
+        params=default_params(),
         selector=None,
         tag=None,
         unit_time=U.year,
@@ -35,11 +35,11 @@ class Comparator(Aggregator, HDF5Container):
         Creates the basic structures needed for the outputs
         """
 
-        super(Comparator, self).__init__(path, path_out, pp_params, tag)
+        super(StudyProcessor, self).__init__(path, path_out, params, tag)
 
         # Open outfile
-        if not self.pp_params.out.tag == "":
-            tag_name = "_" + self.pp_params.out.tag
+        if not self.params.out.tag == "":
+            tag_name = "_" + self.params.out.tag
         else:
             tag_name = ""
 
@@ -48,7 +48,7 @@ class Comparator(Aggregator, HDF5Container):
         # Select runs
         if selector is None:
             selector = RunSelector(
-                path, in_runs, in_nums, self.pp_params.input.nml_filename, **kwargs
+                path, in_runs, in_nums, self.params.input.nml_filename, **kwargs
             )
 
         # Save infos
@@ -57,30 +57,28 @@ class Comparator(Aggregator, HDF5Container):
         self.nums = selector.nums
 
         # Get postprocesor objets for each run and infos on them
-        self.pp = {}
+        self.snaps = {}
         self.info = {}
 
         for run in self.runs:
             path_run = path + "/" + run
             path_out_run = path_out + "/" + run
-            self.pp[run] = {}
+            self.snaps[run] = {}
 
             for num in self.nums[run]:
-                self.pp[run][num] = PostProcessor(
+                self.snaps[run][num] = SnapshotProcessor(
                     path_run,
                     num,
                     path_out=path_out_run,
-                    pp_params=self.pp_params,
+                    params=self.params,
                     unit_time=unit_time,
                 )
 
         run0 = self.runs[0]
-        self.info = self.pp[run0][self.nums[run0][0]].info
-
+        self.info = selector.info[run0][self.nums[run0][0]]
         self.namelist = selector.namelist
-
         # log info
-        self.log_id = "[comp {}] ".format(self.pp_params.out.tag)
+        self.log_id = "[comp {}] ".format(self.params.out.tag)
 
         # Define rules
         self.def_rules()
@@ -107,7 +105,7 @@ class Comparator(Aggregator, HDF5Container):
             return missing_nums
 
     def _save_data(self, name_full, data, description, unit):
-        super(Comparator, self)._save_data(name_full, data, description, unit)
+        super(StudyProcessor, self)._save_data(name_full, data, description, unit)
         self.save.get_node(name_full)._v_attrs.nums = self.nums
 
     def _time_series(self, getter, arg=None):
@@ -194,13 +192,13 @@ class Comparator(Aggregator, HDF5Container):
         }
 
     def get_attr(self, attr_name, run, num, node_name="/", arg=None):
-        pp = self.pp[run][num]
+        pp = self.snaps[run][num]
         if arg is not None:
             node_name = node_name + "_" + str(arg)
         return pp.get_attribute(node_name, attr_name)
 
-    def get_pp_value(self, name, run, num, arg=None):
-        pp = self.pp[run][num]
+    def get_snap_value(self, name, run, num, arg=None):
+        pp = self.snaps[run][num]
         if arg is not None:
             name = name + "_" + str(arg)
         return pp.get_value(name)
@@ -208,7 +206,7 @@ class Comparator(Aggregator, HDF5Container):
     def get_global(self, node_name, run, num, arg=None, unload_cells=False):
         if arg is not None:
             node_name = node_name + "_" + str(arg)
-        pp = self.pp[run][num]
+        pp = self.snaps[run][num]
         if unload_cells:
             pp.unload_cells()
         value = pp.get_value(node_name)
@@ -218,7 +216,7 @@ class Comparator(Aggregator, HDF5Container):
         return self.namelist[run][nml_key]
 
     def get_pdf_slope(self, name, run, num):
-        pp = self.pp[run][num]
+        pp = self.snaps[run][num]
         pp.process(["fit_pdf_" + name], ["z"], overwrite=self.overwrite_dep)
         slope = pp.get_attribute("/hist/pdf_" + name + "_z", "slope")
         return slope
@@ -274,7 +272,7 @@ class Comparator(Aggregator, HDF5Container):
         return series
 
     def _extract_coarse_step_from_log(self, series, log_filename, run):
-        rism = self.pp_params.input.ramses_ism
+        rism = self.params.input.ramses_ism
         nlines = 2 + int(rism)  # Number of useful lines
         cmd_grep = "grep 'Main step\\|coarse step' {} -A {}".format(
             log_filename, nlines - 1
@@ -324,7 +322,7 @@ class Comparator(Aggregator, HDF5Container):
             series["turb_rms"][run].append(np.float(content[i + 1].split(":")[1]))
             try:
                 turb_energy = np.float(content[i + 2].split(":")[1])
-                threshold = self.pp_params.rules.turb_energy_threshold
+                threshold = self.params.rules.turb_energy_threshold
                 assert threshold < 0 or abs(turb_energy) < threshold
                 series["turb_energy"][run].append(abs(turb_energy))
             except (AssertionError, ValueError, IndexError):
@@ -347,7 +345,7 @@ class Comparator(Aggregator, HDF5Container):
             path_run = self.path + "/" + run
 
             # Get list of run files
-            log_files = path_run + "/" + self.pp_params.input.log_prefix + "*"
+            log_files = path_run + "/" + self.params.input.log_prefix + "*"
 
             # Parse files
             for log_filename in glob.glob(log_files):
@@ -372,7 +370,7 @@ class Comparator(Aggregator, HDF5Container):
         ssfr = {}
         for run in self.runs:
             # Surface of the box in pc^2
-            info = self.pp[run][self.nums[run][0]].info
+            info = self.snaps[run][self.nums[run][0]].info
             surface = (info["unit_length"].express(U.pc)) ** 2
             # WARNING : We do not multiply by boxlen since already done in 'unit_length' (pymses)
 
@@ -404,7 +402,7 @@ class Comparator(Aggregator, HDF5Container):
         ssm = {}
         for run in self.runs:
             # Surface of the box in pc^2
-            info = self.pp[run][self.nums[run][0]].info
+            info = self.snaps[run][self.nums[run][0]].info
             surface = (info["unit_length"].express(U.pc)) ** 2
             mass_sink = self.save.get_node(
                 "/series/sinks_from_log/mass_sink/" + run
@@ -441,9 +439,9 @@ class Comparator(Aggregator, HDF5Container):
         for i, run in enumerate(col_pdf["runs"]):
             values, centers = col_pdf["mean"][i]
             mask_fit = (
-                (centers > self.pp_params.pdf.xmin_fit)
-                & (centers < self.pp_params.pdf.xmax_fit)
-                & (values > np.max(values) * self.pp_params.pdf.fit_cut)
+                (centers > self.params.pdf.xmin_fit)
+                & (centers < self.params.pdf.xmax_fit)
+                & (values > np.max(values) * self.params.pdf.fit_cut)
             )
             (slope[i], origin[i], correlation, _, stderr[i]) = linregress(
                 centers[mask_fit], np.log10(values[mask_fit])
@@ -740,4 +738,4 @@ class Comparator(Aggregator, HDF5Container):
         self._gen_rule_avg("rms_from_log", "turb_rms")
         self._gen_rule_avg("rms_from_log", "turb_energy")
 
-        super(Comparator, self).def_rules()
+        super(StudyProcessor, self).def_rules()