/* This is a sample C program which will ask the user for a 4X4 matrix,    */
  /* call a function to compute it's transpose, and output the result.       */

  #include <stdio.h>             /* Include the standard C library functions */

  void transpose(double a[4][4], double t[4][4]);     /* Declare transpose() */

  void main()                                      /* Begin the main program */
  {

    int      i, j;               /* This is the variable declaration section */
    double   a[4][4], t[4][4];

    printf("You will now enter matrix A.\n");

    for (i=0; i<4; i++)                       /* Input matrix from keyboard */
      for (j=0; j<4; j++) {
        printf("Enter matrix element [%d,%d]: ", i, j);
        scanf("%lf", &a[i][j]);
      }

    transpose(a, t);                                    /* Call the function */

    printf("The transpose of matrix A is :\n\n");

    for (i=0; i<4; i++) {                /* Print the results on the screen */
      for (j=0; j<4; j++)
        printf("%lf ", t[i][j]);
      printf("\n");
    }

  }                                                   /* End of main program */

  /* Function to compute the transpose of "a", returning the result in "t".  */
  void transpose(double a[4][4], double t[4][4]) 
  {
    int     row, col;          /* These variables are local to this function */

    for (row=0; row<4; row++)
      for (col=0; col<4; col++)
        t[row][col] = a[col][row];

  }                                                      /* End of function */