Merge pull request #379 from ves-code/ves-interpolation-fix

Fix for bug in TD_GRID

CHANGES/v2.4.md

@@ -193,3 +193,8 @@ For developers:
   - `LDSHARED` is now correctly taken into account when launching `./configure`.
   - Fixed installation with `--disable-shared`.
   - Cppcheck upgraded to 1.84.
+
+## Version 2.4.3 (to be released)
+
+For users:
+  - Module VES: Fixed a bug in TD_GRID for 2D grids where the grid spacing is not the same for both dimensions.

src/ves/GridLinearInterpolation.cpp

@@ -68,8 +68,8 @@ double GridLinearInterpolation::getGridValueWithLinearInterpolation_2D(Grid* gri
   i00[0] = i01[0] = unsigned( std::floor( (arg[0]-grid_min[0])/grid_delta[0] ) );
   i10[0] = i11[0] = unsigned( std::ceil(  (arg[0]-grid_min[0])/grid_delta[0] ) );
 
-  i00[1] = i10[1] = unsigned( std::floor( (arg[1]-grid_min[1])/grid_delta[0] ) );
-  i01[1] = i11[1] = unsigned( std::ceil(  (arg[1]-grid_min[1])/grid_delta[0] ) );
+  i00[1] = i10[1] = unsigned( std::floor( (arg[1]-grid_min[1])/grid_delta[1] ) );
+  i01[1] = i11[1] = unsigned( std::ceil(  (arg[1]-grid_min[1])/grid_delta[1] ) );
 
   // https://en.wikipedia.org/wiki/Bilinear_interpolation
   double x = arg[0];