/*****
 * jims_matrix.c
 *
 * The implementation of the functions.
 * See ./readme.txt for the details.
 *
 * Jim Mahoney | cs.marlboro.edu | Jan 2016 | MIT License
 *****/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "jims_matrix.h"

jmatrix new_jmatrix(int rows, int columns, float* values){
  int n_bytes_for_values = rows * columns * sizeof(float);
  jmatrix m = malloc(sizeof(struct _jmatrix));
  m->rows = rows;
  m->columns = columns;
  m->values = malloc(n_bytes_for_values);
  if (values != NULL){
    memcpy(m->values, values, n_bytes_for_values);
  }
  return m;
}

float jm_get(jmatrix m, int row, int col){
  return (m->values)[ row * m->columns + col ];
}

void jm_set(jmatrix m, int row, int col, float v){
  (m->values)[ row * m->columns + col ] = v;
}

void print_jmatrix(jmatrix m){
  int row, col;
  for (row=0; row < m->rows; row++){
    printf("  ");
    for (col=0; col < m->columns; col++){
      printf("%5.2f ", jm_get(m, row, col));
    }
    printf("\n");
  }
}

void transpose_jmatrix(jmatrix m){
  int row, col;
  float a, b;
  for (row=0; row < m->rows; row++){
    /* loop over top half only, col > row */
    for (col=row+1; col < m->columns; col++){
      a = jm_get(m, row, col);
      b = jm_get(m, col, row);
      jm_set(m, row, col, b);
      jm_set(m, col, row, a);
    }
  }
}

void free_jmatrix(jmatrix m){
  free(m->values);
  free(m);
}