/* A-2; version 1.0 */
/* (c) copyright Ian Hickson 2000, distributed under the GNU GPL */

#include "dynamic-2d-arrays.h"
#include "gauss-elimination.h"

#define Q12 3
#define Q23 1
#define Q24 1
#define Q34 1.5
#define Q41 1
#define Qp1 2
#define Qp2 1
/*#define Qp3 0.5*/
#define Qp4 1.5
#define Cp1 0.02
#define Cp3 0.10

main() {
  array2d* array;
  array2d* answers;
  geNumber value, Qp3;
  int x, y;
  /* allocate memory */
  array = geAllocArray(4);
  /* init array */
  for (x = 0; x < 5; x++) {
    for (y = 0; y < 4; y++) {
      geSet(array, x, y, 0);
    }
  } 
  geSet(array, 0, 0, Q12);
  geSet(array, 3, 0, -Q41);
  geSet(array, 4, 0, Qp1*Cp1);
  geSet(array, 0, 1, Q12);
  geSet(array, 1, 1, -(Q23+Q24+Qp2));
  geSet(array, 1, 2, -Q23);
  geSet(array, 2, 2, Q34);
  /*geSet(array, 4, 2, Qp3*Cp3);*/
  geSet(array, 1, 3, Q24);
  geSet(array, 2, 3, Q34);
  geSet(array, 3, 3, -(Qp4+Q41));

  /* perform loop */
  printf(" Qp3  | C4       \n");
  printf("------+----------\n");
  for (Qp3 = 0.5; Qp3 < 2.1; Qp3 += 0.1) {
    geSet(array, 4, 2, Qp3*Cp3);
    /* do gauss elimination */
    answers = geGaussElimination(array);
    /* dump output */
    value = *(geNumber*)getArray2D(answers, 0, 3);
    printf(" %4.2f | %6.5f", Qp3, value);
    /* deduce critical value */
    if (value > 0.12) {
      printf(" ** DANGER! ** ");
    }
    printf("\n");
    /* free memory for answers */
    freeArray2D(answers);
  }
  /* free all memory */
  freeArray2D(array);
}