add numerical recipes library

lib/nr/ansi/examples/xsprspm.c

@@ -0,0 +1,84 @@
+
+/* Driver for routine sprspm */
+
+#include <stdio.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NP 5
+#define NMAX (2*NP*NP+1)
+
+int main(void)
+{
+	unsigned long i,j,k,*ija,*ijb,*ijbt,*ijc;
+	float *sa,*sb,*sbt,*sc,**a,**b,**c,**ab;
+	static float ainit[NP][NP]={
+		1.0,0.5,0.0,0.0,0.0,
+		0.5,2.0,0.5,0.0,0.0,
+		0.0,0.5,3.0,0.5,0.0,
+		0.0,0.0,0.5,4.0,0.5,
+		0.0,0.0,0.0,0.5,5.0};
+	static float binit[NP][NP]={
+		1.0,1.0,0.0,0.0,0.0,
+		1.0,2.0,1.0,0.0,0.0,
+		0.0,1.0,3.0,1.0,0.0,
+		0.0,0.0,1.0,4.0,1.0,
+		0.0,0.0,0.0,1.0,5.0};
+
+	ija=lvector(1,NMAX);
+	ijb=lvector(1,NMAX);
+	ijbt=lvector(1,NMAX);
+	ijc=lvector(1,NMAX);
+	sa=vector(1,NMAX);
+	sb=vector(1,NMAX);
+	sbt=vector(1,NMAX);
+	sc=vector(1,NMAX);
+	c=matrix(1,NP,1,NP);
+	ab=matrix(1,NP,1,NP);
+	a=convert_matrix(&ainit[0][0],1,NP,1,NP);
+	b=convert_matrix(&binit[0][0],1,NP,1,NP);
+	sprsin(a,NP,0.5,NMAX,sa,ija);
+	sprsin(b,NP,0.5,NMAX,sb,ijb);
+	sprstp(sb,ijb,sbt,ijbt);
+	/* specify tridiagonal output, using fact that a is tridiagonal */
+	for (i=1;i<=ija[ija[1]-1]-1;i++) ijc[i]=ija[i];
+	sprspm(sa,ija,sbt,ijbt,sc,ijc);
+	for (i=1;i<=NP;i++) {
+		for (j=1;j<=NP;j++) {
+			ab[i][j]=0.0;
+			for (k=1;k<=NP;k++) {
+				ab[i][j]=ab[i][j]+a[i][k]*b[k][j];
+			}
+		}
+	}
+	printf("Reference matrix:\n");
+	for (i=1;i<=NP;i++) {
+		for (j=1;j<=NP;j++) printf("%5.2f\t",ab[i][j]);
+		printf("\n");
+	}
+	printf("sprspm matrix (should show only tridiagonals):\n");
+	for (i=1;i<=NP;i++) for (j=1;j<=NP;j++) c[i][j]=0.0;
+	for (i=1;i<=NP;i++) {
+		c[i][i]=sc[i];
+		for (j=ijc[i];j<=ijc[i+1]-1;j++) c[i][ijc[j]]=sc[j];
+	}
+	for (i=1;i<=NP;i++) {
+		for (j=1;j<=NP;j++) printf("%5.2f\t",c[i][j]);
+		printf("\n");
+	}
+	free_convert_matrix(b,1,NP,1,NP);
+	free_convert_matrix(a,1,NP,1,NP);
+	free_matrix(ab,1,NP,1,NP);
+	free_matrix(c,1,NP,1,NP);
+	free_vector(sc,1,NMAX);
+	free_vector(sbt,1,NMAX);
+	free_vector(sb,1,NMAX);
+	free_vector(sa,1,NMAX);
+	free_lvector(ijc,1,NMAX);
+	free_lvector(ijbt,1,NMAX);
+	free_lvector(ijb,1,NMAX);
+	free_lvector(ija,1,NMAX);
+	return 0;
+}
+#undef NRANSI