call Grid_computeVarDiff(integer(in) :: level, integer(in) :: gr_iRefSoln, integer(in) :: gr_iSoln, integer(in) :: ires)
Compute the current difference of two variables. If level is -1, only the leaf block residuals are calculated; otherwise, residuals are computed for all blocks of the given level.
level - the level of blocks to take the residual for, or -1 for all LEAF blocks. gr_iRefSoln - the "reference solution" variable gr_iSoln - "the solution" variable ires - the residual variable
The difference between the reference solution and solution in the blocks (either selected by level, or all LEAF blocks) is placed in the variable ires.