add numerical recipes library

lib/nr/ansi/examples/xlaguer.c

@@ -0,0 +1,47 @@
+
+/* Driver for routine laguer */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "complex.h"
+
+#define M 4     /* degree of polynomial */
+#define MP1 (M+1)   /* no. of polynomial coefficients */
+#define NTRY 21
+#define NTRY1 NTRY+1
+#define EPS 1.e-6
+
+int main(void)
+{
+	fcomplex y[NTRY1],x;
+	static fcomplex a[MP1]={{0.0,2.0},
+				{0.0,0.0},
+				{-1.0,-2.0},
+				{0.0,0.0},
+				{1.0,0.0} };
+	int i,iflag,its,j,n=0;
+
+	printf("\nRoots of polynomial x^4-(1+2i)*x^2+2i\n");
+	printf("\n%15s %15s %7s\n","Real","Complex","#iter");
+	for (i=1;i<=NTRY;i++) {
+		x=Complex((i-11.0)/10.0,(i-11.0)/10.0);
+		laguer(a,M,&x,&its);
+		if (n == 0) {
+			n=1;
+			y[1]=x;
+			printf("%5d %12.6f %12.6f %5d\n",n,x.r,x.i,its);
+		} else {
+			iflag=0;
+			for (j=1;j<=n;j++)
+				if (Cabs(Csub(x,y[j])) <= EPS*Cabs(x)) iflag=1;
+			if (iflag == 0) {
+				y[++n]=x;
+				printf("%5d %12.6f %12.6f %5d\n",n,x.r,x.i,its);
+			}
+		}
+	}
+	return 0;
+}
+#undef NRANSI