Arguments

ierr 		 Return value, negative value indicates theboundary condition was not successfully applied

cctkGH 		 Grid hierarchy pointer

var0 		 Scalar value to apply  (For a complex grid function, this is the real part, 


the imaginary part is set to zero.)

dir 		 Coordinate direction in which to apply boundary condition

stencil_size 		 Array with dimension of the grid function, containing the stencil width

variable_name 		 Name of the variable

group_name 		 Name of the group

variable_index 		 Variable index

group_index 		 Group index