GRBchgcoeffs

int	GRBchgcoeffs (	GRBmodel	*model,
		int	numchgs,
		int	*cind,
		int	*vind,
		double	*val )

Change a set of constraint matrix coefficients. This routine can be used to set a non-zero coefficient to zero, to create a non-zero coefficient where the coefficient is currently zero, or to change an existing non-zero coefficient to a new non-zero value.

Note that the changes won't take effect until the next call to GRBoptimize or GRBupdatemodel.

Return value:

A non-zero return value indicates that a problem occurred while performing the modification. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.

Arguments:

model: The model to modify.

numchgs: The number of coefficients to modify.

cind: Constraint indices for the coefficients to modify.

vind: Variable indices for the coefficients to modify.

val: The new values for the coefficients. For example, if cind[0] = 1, vind[0] = 3, and val[0] = 2.0, then the coefficient in constraint 1 associated with variable 3 would be changed to 2.0.

Example usage:

  int cind[] = {0, 1};
  int vind[] = {0, 0};
  double val[] = {1.0, 1.0};
  error = GRBchgcoeffs(model, 2, cind, vind, val);