add numerical recipes library

lib/nr/ansi/examples/xbandec.c

@@ -0,0 +1,38 @@
+
+/* Driver for routine bandec */
+
+#include <stdio.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+int main(void)
+{
+	float d,**a,**al,*b,*x;
+	unsigned long i,j,*indx;
+	long idum=(-1);
+
+	a=matrix(1,7,1,4);
+	x=vector(1,7);
+	b=vector(1,7);
+	al=matrix(1,7,1,2);
+	indx=lvector(1,7);
+	for (i=1;i<=7;i++) {
+		x[i]=ran1(&idum);
+		for (j=1;j<=4;j++) {
+			a[i][j]=ran1(&idum);
+		}
+	}
+	banmul(a,7,2,1,x,b);
+	for (i=1;i<=7;i++) printf("%ld %12.6f %12.6f\n",i,b[i],x[i]);
+	bandec(a,7,2,1,al,indx,&d);
+	banbks(a,7,2,1,al,indx,b);
+	for (i=1;i<=7;i++) printf("%ld %12.6f %12.6f\n",i,b[i],x[i]);
+	free_lvector(indx,1,7);
+	free_matrix(al,1,7,1,2);
+	free_vector(b,1,7);
+	free_vector(x,1,7);
+	free_matrix(a,1,7,1,4);
+	return 0;
+}
+#undef NRANSI