# get_constraints, get_ptr_constraints

Returns the values of the constraints.

unsigned char get_constraints(lprec *lp, REAL *constr);

unsigned char get_ptr_constraints(lprec *lp, REAL **ptr_constr);

Return Value

get_constraints, get_ptr_constraints returns TRUE (1) if the operation was successful. A return value of FALSE (0) indicates an error.

Parameters

lp

Pointer to previously created lp model. See return value of make_lp, copy_lp, read_lp, read_LP, read_mps, read_freemps, read_MPS, read_freeMPS, read_XLI

constr

An array that will contain the values of the constraints.

ptr_constr

The address of a pointer that will point to an array that will contain the values of the constraints.

Remarks

The get_constraints, get_ptr_constraints functions retrieve the values of the constraints.
These values are only valid after a successful solve or lag_solve. Function get_constraints needs an array that is already dimensioned with get_Nrows elements. get_ptr_constraints returns a pointer to an array already dimensioned by lp_solve. Element 0 will contain the value of the first row, element 1 of the second row, ...
Note that when set_presolve was called with parameter PRESOLVE_LINDEP that this can result in deletion of rows (the linear dependent ones). get_constraints, get_ptr_constraints will then return only the values of the rows that are kept and the values of the deleted rows are not known anymore.

Note that get_ptr_constraints returns a pointer to memory allocated and maintained by lp_solve. Be careful what you do with it. Don't modify its contents or free the memory. Unexpected behaviour would occur. Also note that this memory pointer is only guaranteed to remain constant until a next lp_solve API call is done. You should call this function again to make sure you have again the correct pointer. Otherwise, this pointer could point to invalid memory. This should not be a problem since this call is very efficient.

Example

    #include <stdio.h>
    #include <stdlib.h>
    #include "lp_lib.h"

    int main(void)
    {
      lprec *lp;
      REAL constr[2], *ptr_constr;

      /* Create a new LP model */
      lp = make_lp(2, 2);
      if(lp == NULL) {
        fprintf(stderr, "Unable to create new LP model\n");
        return(1);
      }

      solve(lp);

      get_constraints(lp, constr);
      get_ptr_constraints(lp, &ptr_constr);

      delete_lp(lp);
      return(0);
    }

lp_solve API reference

See Also make_lp, copy_lp, read_lp, read_LP, read_mps, read_freemps, read_MPS, read_freeMPS, read_XLI, is_feasible, get_objective, get_working_objective, get_variables, get_ptr_variables, get_primal_solution, get_ptr_primal_solution, get_var_primalresult, get_constr_value, get_sensitivity_rhs, get_ptr_sensitivity_rhs, get_dual_solution, get_ptr_dual_solution, get_var_dualresult, get_sensitivity_obj, get_ptr_sensitivity_obj, get_sensitivity_objex, get_ptr_sensitivity_objex,