Thread: Memory problem

Provide the smallest and simplest compilable code that demonstrates the error.

You could post the code?

You can be sure that your computer has enough memory to hold more than 30 variables

How can I free some memory? After I use a variable, and no longer need it, is there any way to sort of "get back" the memory it used?

If the variable is a pointer that points to dynamically allocated memory, then you should use free() appropriately. If not, then perhaps you have one monolithic function that needs to be broken up. The side effect would be that the various local variables would then have scopes limited to the functions that they belong to, and thus their lifetimes would be correspondingly limited.

Now when I repasted it, the smaller code is not working either. Let me post everything...



Sorry for the complex variables...
main program:

Code:

#include<stdio.h>
#include<math.h>

#include"vect_pinv2.c"

#define Pi 3.14159265

int main()

{


int M=3, cluster_number=2;
double AS_deg[1][2]={20, 35};
double phi_deg[1][2]={25,20};
double delta_phi_deg[1][2]={90, 90};
double amplitude_cluster[1][2]={20, 30};
double sigma_deg[1][2]={20, 31};

/*int PAS_type=2;*/
/*double d_norm[1][3]={0, 0.5, 1};*/
/*double Q[1][2]={0.096, 0.1891};*/

int m;
int i,j,k;
double C;
double result_xx[100][M];
double result_xy[100][M];
double tmp_xx_gaussian[100][M];
double tmp_xy_gaussian[100][M];
double phi_rad[1][cluster_number], sigma_rad[1][cluster_number];
double delta_phi_rad[1][cluster_number];
double Ar[100][cluster_number];
double Ai[100][cluster_number];
double pinv[1][cluster_number], n, x, y;
double erfr1, erfi1, erfr2, erfi2;
char z[15];

	
	/*-----------------------Rxx and Rxy uniform-----------------*/
		
			/*Conversion degree -> radian*/

			for(j=0;j<cluster_number;j++)
			{
				phi_rad[0][j]=phi_deg[0][j]*(Pi/180);
				sigma_rad[0][j]=sigma_deg[0][j]*(Pi/180)*sqrt(2);
				delta_phi_rad[0][j]=delta_phi_deg[0][j]*(Pi/180);
			}
			
			vect_pinv(cluster_number, sigma_rad, pinv);
	

			for(j=0; j<cluster_number; j++)
			{
				C+=(delta_phi_rad[0][j]*pinv[0][j]);
				printf("&#37;.4lf\t", pinv[0][j]);
			}printf("%.4lf\t", C);


	return 0;

}

vect_inv.c (function code)

Code:

#include<stdio.h>

double vect_pinv(int cluster_number, double sigma_rad[1][cluster_number], double pinv[1][cluster_number])
{
	int i;
	double mag;

	for(i=0;i<cluster_number;i++)
	mag+= (sigma_rad[0][i]*sigma_rad[0][i]);

	for(i=0;i<cluster_number;i++)
	{
		pinv[0][i]= sigma_rad[0][i]/mag;
	}

	return 3;
}

Something's wrong with my variable C, I think...but what?

It looks like you have a whole bunch of unused variables. Also, do you really need variable length arrays? It seems like cluster_number should be const instead. I am also puzzled as to why you write:

Code:

double AS_deg[1][2]={20, 35};

instead of:

Code:

double AS_deg[2]={20, 35};

The cluster number is user dependent

In that case you might want to use dynamic memory allocation with malloc() and free() instead of variable length arrays. This would allow you to control precisely when you create and destroy these arrays.

I can't remember why my arrays are [1][2], but I think there was a good reason for it. Would it really make a huge difference if I changed that?

Probably not, but if you cannot remember the reason and did not bother to document it, then perhaps it was not such a good reason after all, so you might as well simplify your code.