Add check for vmin, vmax in plot_surf_roi (nilearn#2052)

* added check for vmin, vmax

Passed vmin, vmax values were being overwritten by default values. Added check to use default vmin, vmax if no parameters are passed

* remove commented out code

* unit test for plot_surf_roi

* add plot_surf_roi fixes to whats_new

doc/whats_new.rst

@@ -67,6 +67,7 @@ Fixes
 - :func:`nilearn.plotting.view_surf` now accepts surface data provided as a file
   path.
 - :func:`nilearn.plotting.plot_matrix` providing labels=None, False, or an empty list now correctly disables labels.
+- :func:`nilearn.plotting.plot_surf_roi` now takes vmin, vmax parameters
 - :func:`nilearn.datasets.fetch_surf_nki_enhanced` is now downloading the correct
   left and right functional surface data for each subject
 - :func:`nilearn.datasets.fetch_atlas_schaefer_2018` now downloads from release

nilearn/plotting/surf_plotting.py

@@ -514,7 +514,10 @@ def plot_surf_roi(surf_mesh, roi_map, bg_map=None,
     # messages in case of wrong inputs
 
     roi = load_surf_data(roi_map)
-    vmin, vmax = np.min(roi), 1 + np.max(roi)
+    if vmin is None:
+        vmin = np.min(roi)
+    if vmax is None:
+        vmax = 1 + np.max(roi)
 
     mesh = load_surf_mesh(surf_mesh)
 

nilearn/plotting/tests/test_surf_plotting.py

@@ -162,6 +162,14 @@ def test_plot_surf_roi():
     # plot roi
     plot_surf_roi(mesh, roi_map=roi_map)
     plot_surf_roi(mesh, roi_map=roi_map, colorbar=True)
+    # change vmin, vmax
+    img = plot_surf_roi(mesh, roi_map=roi_map,
+						vmin=1.2, vmax=8.9, colorbar=True)
+    cbar = img.axes[-1]
+    cbar_vmin = float(cbar.get_yticklabels()[0].get_text())
+    cbar_vmax = float(cbar.get_yticklabels()[-1].get_text())
+    assert cbar_vmin == 1.2
+    assert cbar_vmax == 8.9
 
     # plot parcellation
     plot_surf_roi(mesh, roi_map=parcellation)