Add warnings when adding inertia and hydrostatic stiffness automatica…

…lly (sandialabs#346)

wecopttool/core.py

@@ -2175,8 +2175,16 @@ def run_bem(
     wec_im = fb.copy(name=f"{fb.name}_immersed").keep_immersed_part()
     wec_im = set_fb_centers(wec_im, rho=rho)
     if not hasattr(wec_im, 'inertia_matrix'):
+        _log.warning('FloatingBody has no inertia_matrix field. ' + 
+                     'If the FloatingBody mass is defined, it will be ' + 
+                     'used for calculating the inertia matrix here. ' + 
+                     'Otherwise, the neutral buoyancy assumption will ' + 
+                     'be used to auto-populate.')
         wec_im.inertia_matrix = wec_im.compute_rigid_body_inertia(rho=rho)
     if not hasattr(wec_im, 'hydrostatic_stiffness'):
+        _log.warning('FloatingBody has no hydrostatic_stiffness field. ' +
+                     'Capytaine will auto-populate the hydrostatic ' +
+                     'stiffness based on the provided mesh.')
         wec_im.hydrostatic_stiffness = wec_im.compute_hydrostatic_stiffness(rho=rho, g=g)
     bem_data = solver.fill_dataset(
         test_matrix, wec_im, n_jobs=njobs, **write_info)