Merge PR #416 (Implement fix in gcpy/regrid.py for numpy)

This merge brings PR #416 (Implement fix in gcpy/regrid.py for numpy
backward compatibility, by @yantosca) into the GCPy development stream.

PR #146 adds a try/except block (in routine regrid_vertical of
gcpy/regrid.py) to first call np.prod, and then if that fails,
to call np.product.  The np.product routine was renamed to np.prod
in Numpy 2.0.  This will ensure backwards compatibility with older
Numpy versions.

Signed-off-by: Bob Yantosca <yantosca@seas.harvard.edu>

Author: yantosca

CHANGELOG.md

@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Fixed
 - Allow using a template at different grid resolutions in `gcpy/regrid_restart_file.py`
+- Implemented a workaround in `gcpy/regrid.py` to allow use of either `np.product` or `np.prod` depending on the Numpy version
 
 ## [1.7.1] - 2026-02-03
 ### Changed

gcpy/regrid.py

@@ -1094,7 +1094,14 @@ def regrid_vertical(src_data_3d, xmat_regrid, target_levs=None):
 
     nlev_out = xmat_renorm.shape[1]
     out_shape = [nlev_out] + list(src_data_3d.shape[1:])
-    n_other = np.product(src_data_3d.shape[1:])
+    # ------------------------------------------------------------------
+    # The np.product function was changed to np.prod in version 2.0,
+    # so implement this workaround for backward compatibility.
+    try:
+        np_other = np.prod(src_data_3d.shape[1:])      # NumPy >= 2.0
+    except AttributeError:
+        np_other = np.product(src_data_3d.shape[1:])   # NumPy < 2.0
+    # ------------------------------------------------------------------
     temp_data = np.zeros((nlev_out, n_other))
     in_data = np.reshape(np.array(src_data_3d), (nlev_in, n_other))
     for ix in range(n_other):