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/rstrct.cpp
+++ b/lib/nr/cpp/recipes/rstrct.cpp
@@ -0,0 +1,23 @@
+#include "nr.h"
+
+void NR::rstrct(Mat_O_DP &uc, Mat_I_DP &uf)
+{
+	int ic,iif,jc,jf,ncc;
+
+	int nc=uc.nrows();
+	ncc=2*nc-2;
+	for (jf=2,jc=1;jc<nc-1;jc++,jf+=2) {
+		for (iif=2,ic=1;ic<nc-1;ic++,iif+=2) {
+			uc[ic][jc]=0.5*uf[iif][jf]+0.125*(uf[iif+1][jf]+uf[iif-1][jf]
+				+uf[iif][jf+1]+uf[iif][jf-1]);
+		}
+	}
+	for (jc=0,ic=0;ic<nc;ic++,jc+=2) {
+		uc[ic][0]=uf[jc][0];
+		uc[ic][nc-1]=uf[jc][ncc];
+	}
+	for (jc=0,ic=0;ic<nc;ic++,jc+=2) {
+		uc[0][ic]=uf[0][jc];
+		uc[nc-1][ic]=uf[ncc][jc];
+	}
+}