add numerical recipes library

lib/nr/k_and_r/recipes/qromo.c

@@ -0,0 +1,31 @@
+
+#include <math.h>
+#define EPS 1.0e-6
+#define JMAX 14
+#define JMAXP (JMAX+1)
+#define K 5
+
+float qromo(func,a,b,choose)
+float (*choose)(),(*func)(),a,b;
+{
+	void polint();
+	void nrerror();
+	int j;
+	float ss,dss,h[JMAXP+1],s[JMAXP];
+
+	h[1]=1.0;
+	for (j=1;j<=JMAX;j++) {
+		s[j]=(*choose)(func,a,b,j);
+		if (j >= K) {
+			polint(&h[j-K],&s[j-K],K,0.0,&ss,&dss);
+			if (fabs(dss) <= EPS*fabs(ss)) return ss;
+		}
+		h[j+1]=h[j]/9.0;
+	}
+	nrerror("Too many steps in routing qromo");
+	return 0.0;
+}
+#undef EPS
+#undef JMAX
+#undef JMAXP
+#undef K