add numerical recipes library

2025-09-12 18:55:25 +09:00
parent d4dff245bd
commit 2c75620ec9
1344 changed files with 63869 additions and 0 deletions
--- a/lib/nr/cpp/recipes/chint.cpp
+++ b/lib/nr/cpp/recipes/chint.cpp
@@ -0,0 +1,17 @@
+#include "nr.h"
+
+void NR::chint(const DP a, const DP b, Vec_I_DP &c, Vec_O_DP &cint, const int n)
+{
+	int j;
+	DP sum=0.0,fac=1.0,con;
+
+	con=0.25*(b-a);
+	for (j=1;j<n-1;j++) {
+		cint[j]=con*(c[j-1]-c[j+1])/j;
+		sum += fac*cint[j];
+		fac = -fac;
+	}
+	cint[n-1]=con*c[n-2]/(n-1);
+	sum += fac*cint[n-1];
+	cint[0]=2.0*sum;
+}