problems with arrays

Hi Pals, well my new problem is that I would like the output of my code as an array,and I dont get it at all, I would like to have the results of u[1][1] u[1][2] u[1][3] in my output
thanks

Code:

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/*Heat equation explicit scheme */
#include <stdio.h>
#include<stdlib.h>
#include<math.h>
#define max 100
#define pi 4*atan(1)
int
main ()
{
        FILE *heat;
        float t[max],x[max],u[max][max],k,h,r,s;
        float tmax;
        int n,j,m,i;
        float xmax,nstep,alpha;
        /*printf("enter the value of L=");scanf("%d",xmax);*/
        /*printf(" steps of x=");scanf("%f",nstep);*/
        /*printf("maximun value of Tmax");scanf("%d",tmax);*/
        /*printf("enter alpha");scanf("%d",alpha);*/
        xmax=1;
        nstep=2;
        tmax=0.5;
        alpha=1;
        heat=fopen("heat.data","w");
        /* Estability*/
        /*h=xmax/nstep;*/
        h=xmax/nstep;
        k=0.5*h*h/alpha;
        m=3;
        n=2;
       
       
        /* Boundary Conditions*/
        for(j=0;j<=m;j++)
        {
                t[j]=j*k;
                u[0][j]=0;
                u[n][j]=0;
               
        }
        /*Initial Conditions*/
        for(j=1;j<=n-1;j++)
        {
                x[j]=j*h;
                u[j][0]=10*sin(pi*x[j]*0.5);
        }
        /*Aproximations*/
        r=alpha*k/k*h;
        s=1-2*r;
        for(j=1;j<=m;j++)
        {
                for(i=1;i<=n-1;i++)
               
                u[i][j]=s*u[i][j-1]+r*u[i-1][j-1]+r*u[i+1][j-1];       
               
               
               
        }
        for(j=0;j<=m;j++)
        {
                for(i=0;i<=n;i++)
               
                        fprintf(heat,"%1.5f\n%1.5f\t",t[j],u[i][j]);
                        /*printf("\n");*/
               
        }
       
        fclose(heat);
        exit (0);
}

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Code:

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#define pi 4*atan(1)

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Do you REALLY want to call a function and then multiply by 4 every time you use PI, simply because you can't be bothered to look up/type in the value of PI? Further, since you are using float rather than double, you only need about 6 decimal places, so 3.1415926 would do fine.

As to the other problem: What ARE you getting?

--
Mats

what i need is my output as an array I dont know how can i get

my problems is in the output of this code, I would like to have u[i][j] as an array in the output, it should be possible to do this?

Code:

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fprintf(heat,"%1.5f\n%1.5f\t",t[j],u[i][j]);

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Sorry, but what you do mean by "as an array"? fprintf (and it's friends) can only output one item for each % format specifier.

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Mats