#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <malloc.h>
#include <sys/time.h>
#include <gsl/gsl_blas.h>

//tolerance for result of CG
#define TOLERANCE 1e-6
//max iteration by CG
#define MAX_ITRN 100
//max file name length
#define MAX_FILE_LEN 80
#define MILLISECOND 1000000.0

struct Vector
{
	int n;		//number of elements
	float *p;	//values
};
typedef struct Vector Vec;

struct Matrix
{
	int n;		//# of rows
	int m;		//# of columns
	float *p;	//values
};
typedef struct Matrix Mat;

//========== Vec/Mat allocation and free ====
Vec * createVec(int n);
void destroyVec(Vec * vecP);
Mat * createMat(int n, int m);
void destroyMat(Mat * matP);

//========== Vec/Mat io =====================
Vec * readVec(FILE * vecInFile);
void writeVec(Vec * vecP, FILE * outFile);
Mat * readMat(FILE * matInFile);
void writeMat(Mat * matP, FILE * outFile);

//========== CG functions ===================
Vec * CG(const gsl_matrix_float * A, const gsl_vector_float * b, float tol, int maxItn);