added checkes to GCI function

Author: browniea

mhkit/river/io/d3d.py

@@ -915,6 +915,8 @@ def calculate_grid_convergence_index(
         Results from the coarser grid.
     refinement_ratio: float
         Refinement ratio between the grids.
+    factor_of_safety: float
+        Factor of safety (default is 1.25).
     order: int
         Order of accuracy (default is 2).
 
@@ -923,6 +925,19 @@ def calculate_grid_convergence_index(
     gci: float
         Grid Convergence Index (GCI).
     """
+
+    # Validate inputs
+    if not (np.issubdtype(refinement_ratio.dtype, np.number)):
+        raise TypeError("refinement_ratio must be a numeric values")
+    if not (np.issubdtype(factor_of_safety.dtype, np.number)):
+        raise TypeError("factor_of_safety must be a numeric values")
+    if not (np.issubdtype(order.dtype, np.number)):
+        raise TypeError("order must be a numeric values")
+    if not (np.issubdtype(fine_grid.dtype, np.number) and np.issubdtype(coarse_grid.dtype, np.number)):
+        raise TypeError("fine_grid and coarse_grid must contain numeric values")
+    if fine_grid.shape != coarse_grid.shape:
+        raise ValueError("fine_grid and coarse_grid must have the same shape")
+
     # Calculate the approximate relative error
     error = np.abs((fine_grid - coarse_grid) / fine_grid)