/* Driver for routine splie2 */ #include #define NRANSI #include "nr.h" #include "nrutil.h" #define M 10 #define N 10 int main(void) { int i,j; float x1x2,*x1,*x2,**y,**y2; x1=vector(1,N); x2=vector(1,N); y=matrix(1,M,1,N); y2=matrix(1,M,1,N); for (i=1;i<=M;i++) x1[i]=0.2*i; for (i=1;i<=N;i++) x2[i]=0.2*i; for (i=1;i<=M;i++) for (j=1;j<=N;j++) { x1x2=x1[i]*x2[j]; y[i][j]=x1x2*x1x2; } splie2(x1,x2,y,M,N,y2); printf("\nsecond derivatives from SPLIE2\n"); printf("natural spline assumed\n"); for (i=1;i<=5;i++) { for (j=1;j<=5;j++) printf("%12.6f",y2[i][j]); printf("\n"); } printf("\nactual second derivatives\n"); for (i=1;i<=5;i++) { for (j=1;j<=5;j++) printf("%12.6f",2.0*x1[i]*x1[i]); printf("\n"); } free_matrix(y2,1,M,1,N); free_matrix(y,1,M,1,N); free_vector(x2,1,N); free_vector(x1,1,N); return 0; } #undef NRANSI