add numerical recipes library

lib/nr/k_and_r/recipes/tptest.c

@@ -0,0 +1,21 @@
+
+#include <math.h>
+
+void tptest(data1,data2,n,t,prob)
+float *prob,*t,data1[],data2[];
+unsigned long n;
+{
+	float betai();
+	void avevar();
+	unsigned long j;
+	float var1,var2,ave1,ave2,sd,df,cov=0.0;
+
+	avevar(data1,n,&ave1,&var1);
+	avevar(data2,n,&ave2,&var2);
+	for (j=1;j<=n;j++)
+		cov += (data1[j]-ave1)*(data2[j]-ave2);
+	cov /= df=n-1;
+	sd=sqrt((var1+var2-2.0*cov)/n);
+	*t=(ave1-ave2)/sd;
+	*prob=betai(0.5*df,0.5,df/(df+(*t)*(*t)));
+}