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/bksub.cpp
+++ b/lib/nr/cpp/recipes/bksub.cpp
@@ -0,0 +1,25 @@
+#include "nr.h"
+
+void NR::bksub(const int ne, const int nb, const int jf, const int k1,
+	const int k2, Mat3D_IO_DP &c)
+{
+	int nbf,im,kp,k,j,i;
+	DP xx;
+
+	nbf=ne-nb;
+	im=1;
+	for (k=k2-1;k>=k1;k--) {
+		if (k == k1) im=nbf+1;
+		kp=k+1;
+		for (j=0;j<nbf;j++) {
+			xx=c[j][jf][kp];
+			for (i=im-1;i<ne;i++)
+				c[i][jf][k] -= c[i][j][k]*xx;
+		}
+	}
+	for (k=k1;k<k2;k++) {
+		kp=k+1;
+		for (i=0;i<nb;i++) c[i][0][k]=c[i+nbf][jf][k];
+		for (i=0;i<nbf;i++) c[i+nb][0][k]=c[i][jf][kp];
+	}
+}