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/eigsrt.cpp
+++ b/lib/nr/cpp/recipes/eigsrt.cpp
@@ -0,0 +1,23 @@
+#include "nr.h"
+
+void NR::eigsrt(Vec_IO_DP &d, Mat_IO_DP &v)
+{
+	int i,j,k;
+	DP p;
+
+	int n=d.size();
+	for (i=0;i<n-1;i++) {
+		p=d[k=i];
+		for (j=i;j<n;j++)
+			if (d[j] >= p) p=d[k=j];
+		if (k != i) {
+			d[k]=d[i];
+			d[i]=p;
+			for (j=0;j<n;j++) {
+				p=v[j][i];
+				v[j][i]=v[j][k];
+				v[j][k]=p;
+			}
+		}
+	}
+}