Make get_spatial_windows() more easier for small probes.

Ensure one window and no more fails.

Author: samuelgarcia

src/spikeinterface/preprocessing/tests/test_motion.py

@@ -58,7 +58,7 @@ def test_compute_motion_fails(create_cache_folder):
     is `None`.
     """
     # this recording has too few channels for the motion correction to work
-    rec = generate_recording(durations=[5])
+    rec = generate_recording(durations=[5], num_channels=1)
     motion, motion_info = compute_motion(rec, raise_error=False, output_motion_info=True)
 
     assert motion is None
@@ -80,5 +80,8 @@ def test_compute_motion_fails(create_cache_folder):
 if __name__ == "__main__":
     # print(correct_motion.__doc__)
     # test_estimate_and_correct_motion()
-    test_get_motion_parameters_preset()
-    test_compute_motion_fails()
+    # test_get_motion_parameters_preset()
+    from pathlib import Path
+    cache_folder = Path(__file__).resolve().parents[4] / "cache_folder" / "preprocessing"
+    test_compute_motion_fails(cache_folder)
+

src/spikeinterface/sortingcomponents/motion/motion_utils.py

@@ -78,10 +78,13 @@ def get_spatial_windows(
         num_windows = int((max_ - min_) // win_step_um)
 
         if num_windows < 1:
-            raise Exception(
+            num_windows = 1
+            warnings.warn(
+                f"You trying to estimation motion with non-rigid on a too short probe!"
                 f"get_spatial_windows(): {win_step_um=}/{win_scale_um=}/{win_margin_um=} are too large for the "
                 f"probe size (depth range={np.ptp(contact_depths)}). You can try to reduce them or use rigid motion."
             )
+
         border = ((max_ - min_) % win_step_um) / 2
         window_centers = np.arange(num_windows + 1) * win_step_um + min_ + border
         windows = []