/* Read a matrix in from FileName 
structure definition is in Matrix.h 
*/
#include "Matrix.h"

struct matrix ReadMatrix(char FileName[]){
	FILE   *FilePointer;
	int    i,j,m,n;
	struct matrix A = {0,0, NULL}; 
	
	/* Opens file checks pointer is OK */
	FilePointer = fopen(FileName,"r");
	if(FilePointer==NULL){
		fprintf(stderr, "ReadMatrix %s: File problem\n",FileName); 
		return A;};
	/* Checks file header is appropriate.
	NOTE:  currently assumes float!
	*/
	i=fscanf(FilePointer, "5903FullMatrix %i %i float", &m,&n);
	if(i!=2){
		fprintf(stderr, "ReadMatrix %s: Memory problem\n",FileName); 
		return A;
		};
	/* Assigns memory and fills the array 
	NOTE:  currently assumes float!
	*/
	A=InitializeMatrix(m, n);
	for(i=0;i<m;i++) {
		for(j=0;j<n;j++){
			fscanf(FilePointer,"%g", &A.mat[i][j]);
				};
			};
	/* closes file */
	fclose(FilePointer);
	/* Returns A */
	return A;
}