[plotter] [map] Uses im_extent information to the speed overlay. Fixes #1

plotter.py

@@ -701,36 +701,41 @@ 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
-        radius = self.save.root.maps._v_attrs.radius
-        center = self.save.root.maps._v_attrs.center
-        lbox = self.save.root._v_attrs.lbox
 
-        map_vh_red = dmap_vh[::vel_red, ::vel_red] * unit_old.express(
+        # take only a subset of velocities
-            unit
+        map_vh_red = dmap_vh[::vel_red, ::vel_red] * unit_old.express(unit)
-        )  # take only a subset of velocities
         map_vv_red = dmap_vv[::vel_red, ::vel_red] * unit_old.express(unit)
 
-        # TODO : redo this with im_extent
+        # get norm infomartion
-
-        nh = map_vh_red.shape[0]
-        nv = map_vv_red.shape[1]
-        vec_h = (
-            np.arange(nh) * 2.0 / nh * radius - radius + center[0] + radius / nh
-        ) * lbox
-        vec_v = (
-            np.arange(nv) * 2.0 / nv * radius - radius + center[1] + radius / nv
-        ) * lbox
-        hh, vv = np.meshgrid(vec_h, vec_v)
         norm_v = np.sqrt(map_vh_red ** 2 + map_vv_red ** 2)
         max_v = np.max(norm_v)
         min_v = np.min(norm_v)
 
-        Q = plt.quiver(hh, vv, map_vh_red, map_vv_red, units="width", **kwargs)
+        # Number of selected vectors
+        nh = map_vh_red.shape[0]
+        nv = map_vh_red.shape[1]
 
+        # Creates vectors position grid
+        size_h = im_extent[1] - im_extent[0]  # size of the map
+        dh = size_h / dmap_vh.shape[0]  # size of cell
+        seph = size_h / nh  # separation between vectors
+        h = im_extent[0] + dh + np.arange(nh) * seph
+
+        size_v = im_extent[3] - im_extent[2]
+        dv = size_v / dmap_vh.shape[1]
+        sepv = size_v / nv
+        v = im_extent[2] + dv + np.arange(nv) * sepv
+
+        hh, vv = np.meshgrid(h, v)
+
+        # plot vector field
+        vec_field = plt.quiver(hh, vv, map_vh_red, map_vv_red, units="width", **kwargs)
+
+        # add vector key
         if key_v is None:
             key_v = (max_v + min_v) / 2.0
         plt.quiverkey(
-            Q,
+            vec_field,
             0.6,
             0.98,
             key_v,