55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
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/* Driver for routine mprove */
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#include <stdio.h>
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#define NRANSI
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#include "nr.h"
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#include "nrutil.h"
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#define N 5
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#define NP N
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int main(void)
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{
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int i,j,*indx;
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long idum=(-13);
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float d,*x,**a,**aa;
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static float ainit[NP][NP]=
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{1.0,2.0,3.0,4.0,5.0,
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2.0,3.0,4.0,5.0,1.0,
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1.0,1.0,1.0,1.0,1.0,
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4.0,5.0,1.0,2.0,3.0,
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5.0,1.0,2.0,3.0,4.0};
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static float b[N+1]={0.0,1.0,1.0,1.0,1.0,1.0};
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indx=ivector(1,N);
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x=vector(1,N);
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a=convert_matrix(&ainit[0][0],1,N,1,N);
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aa=matrix(1,N,1,N);
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for (i=1;i<=N;i++) {
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x[i]=b[i];
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for (j=1;j<=N;j++)
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aa[i][j]=a[i][j];
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}
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ludcmp(aa,N,indx,&d);
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lubksb(aa,N,indx,x);
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printf("\nSolution vector for the equations:\n");
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for (i=1;i<=N;i++) printf("%12.6f",x[i]);
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printf("\n");
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/* now phoney up x and let mprove fix it */
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for (i=1;i<=N;i++) x[i] *= (1.0+0.2*ran3(&idum));
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printf("\nSolution vector with noise added:\n");
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for (i=1;i<=N;i++) printf("%12.6f",x[i]);
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printf("\n");
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mprove(a,aa,N,indx,b,x);
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printf("\nSolution vector recovered by mprove:\n");
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for (i=1;i<=N;i++) printf("%12.6f",x[i]);
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printf("\n");
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free_matrix(aa,1,N,1,N);
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free_convert_matrix(a,1,N,1,N);
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free_vector(x,1,N);
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free_ivector(indx,1,N);
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return 0;
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}
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#undef NRANSI
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