add numerical recipes library

lib/nr/ansi/recipes/crank.c

@@ -0,0 +1,22 @@
+
+void crank(unsigned long n, float w[], float *s)
+{
+	unsigned long j=1,ji,jt;
+	float t,rank;
+
+	*s=0.0;
+	while (j < n) {
+		if (w[j+1] != w[j]) {
+			w[j]=j;
+			++j;
+		} else {
+			for (jt=j+1;jt<=n && w[jt]==w[j];jt++);
+			rank=0.5*(j+jt-1);
+			for (ji=j;ji<=(jt-1);ji++) w[ji]=rank;
+			t=jt-j;
+			*s += t*t*t-t;
+			j=jt;
+		}
+	}
+	if (j == n) w[n]=n;
+}