[FIX] validate input value symmetric_cbar

nilearn/_utils/param_validation.py

@@ -83,6 +83,23 @@
     return threshold
 
 
+def check_symmetric_cbar(symmetric_cbar):
+    """Check value of symmetric_cbar."""
+    if symmetric_cbar is None:
+        symmetric_cbar = "auto"
+    if not isinstance(symmetric_cbar, (bool, str)):
+        raise ValueError(
+            "'symmetric_cbar' must be a boolean or 'auto'.\n"
+            f"got: {symmetric_cbar}"
+        )
+    if isinstance(symmetric_cbar, str) and symmetric_cbar != "auto":
+        raise ValueError(
+            "'symmetric_cbar' must be a boolean or 'auto'.\n"
+            f"got: {symmetric_cbar}"
+        )
+    return symmetric_cbar
+
+
 def get_mask_volume(mask_img):
     """Compute the volume of a brain mask in mm^3.
 

nilearn/plotting/img_plotting.py

@@ -38,7 +38,7 @@
 from .._utils.ndimage import get_border_data
 from .._utils.niimg import safe_get_data
 from .._utils.numpy_conversions import as_ndarray
-from .._utils.param_validation import check_threshold
+from .._utils.param_validation import check_symmetric_cbar, check_threshold
 from ..datasets import load_mni152_template
 from ..image import get_data, iter_img, math_img, new_img_like, resample_to_img
 from ..masking import apply_mask, compute_epi_mask
@@ -1313,6 +1313,8 @@ def plot_stat_map(
 
     stat_map_img = _utils.check_niimg_3d(stat_map_img, dtype="auto")
 
+    symmetric_cbar = check_symmetric_cbar(symmetric_cbar)
+
     cbar_vmin, cbar_vmax, vmin, vmax = get_colorbar_and_data_ranges(
         safe_get_data(stat_map_img, ensure_finite=True),
         vmin=vmin,
@@ -1455,6 +1457,8 @@ def plot_glass_brain(
                 cmap(np.linspace(0.5, 1, 256)),
             )
 
+    symmetric_cbar = check_symmetric_cbar(symmetric_cbar)
+
     if stat_map_img:
         stat_map_img = _utils.check_niimg_3d(stat_map_img, dtype="auto")
         if plot_abs:

nilearn/plotting/surf_plotting.py

@@ -17,6 +17,7 @@
 from nilearn import image, surface
 from nilearn._utils import check_niimg_3d, compare_version, fill_doc
 from nilearn._utils.helpers import is_kaleido_installed, is_plotly_installed
+from nilearn._utils.param_validation import check_symmetric_cbar
 from nilearn.plotting.cm import cold_hot, mix_colormaps
 from nilearn.plotting.displays._slicers import _get_cbar_ticks
 from nilearn.plotting.html_surface import get_vertexcolor
@@ -1201,6 +1202,7 @@ def plot_surf_stat_map(surf_mesh, stat_map, bg_map=None,
     nilearn.surface.vol_to_surf : For info on the generation of surfaces.
 
     """
+    symmetric_cbar = check_symmetric_cbar(symmetric_cbar)
     check_extensions(stat_map, DATA_EXTENSIONS, FREESURFER_DATA_EXTENSIONS)
     loaded_stat_map = load_surf_data(stat_map)
 
@@ -1453,6 +1455,8 @@ def plot_img_on_surf(stat_map, surf_mesh='fsaverage5', mask_img=None,
     hemis = _check_hemispheres(hemispheres)
     surf_mesh = check_mesh(surf_mesh)
 
+    symmetric_cbar = check_symmetric_cbar(symmetric_cbar)
+
     mesh_prefix = "infl" if inflate else "pial"
     surf = {
         'left': surf_mesh[f'{mesh_prefix}_left'],

nilearn/plotting/tests/test_img_plotting/test_plot_stat_map.py

@@ -27,6 +27,17 @@ def test_plot_stat_map_bad_input(img_3d_mni, tmp_path):
     plt.close()
 
 
+def test_plot_stat_map_invalid_symmetric_cbar(img_3d_mni):
+    """Test for bad input for symmetric_cbar."""
+    with pytest.raises(
+        ValueError, match="'symmetric_cbar' must be a boolean or 'auto'"
+    ):
+        plot_stat_map(
+            img_3d_mni,
+            symmetric_cbar=1,
+        )
+
+
 @pytest.mark.parametrize(
     "params", [{}, {"display_mode": "x", "cut_coords": 3}]
 )