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/savgol.cpp
+++ b/lib/nr/cpp/recipes/savgol.cpp
@@ -0,0 +1,35 @@
+#include <cmath>
+#include "nr.h"
+using namespace std;
+
+void NR::savgol(Vec_O_DP &c, const int np, const int nl, const int nr,
+	const int ld, const int m)
+{
+	int j,k,imj,ipj,kk,mm;
+	DP d,fac,sum;
+
+	if (np < nl+nr+1 || nl < 0 || nr < 0 || ld > m || nl+nr < m)
+		nrerror("bad args in savgol");
+	Vec_INT indx(m+1);
+	Mat_DP a(m+1,m+1);
+	Vec_DP b(m+1);
+	for (ipj=0;ipj<=(m << 1);ipj++) {
+		sum=(ipj ? 0.0 : 1.0);
+		for (k=1;k<=nr;k++) sum += pow(DP(k),DP(ipj));
+		for (k=1;k<=nl;k++) sum += pow(DP(-k),DP(ipj));
+		mm=MIN(ipj,2*m-ipj);
+		for (imj = -mm;imj<=mm;imj+=2) a[(ipj+imj)/2][(ipj-imj)/2]=sum;
+	}
+	ludcmp(a,indx,d);
+	for (j=0;j<m+1;j++) b[j]=0.0;
+	b[ld]=1.0;
+	lubksb(a,indx,b);
+	for (kk=0;kk<np;kk++) c[kk]=0.0;
+	for (k = -nl;k<=nr;k++) {
+		sum=b[0];
+		fac=1.0;
+		for (mm=1;mm<=m;mm++) sum += b[mm]*(fac *= k);
+		kk=(np-k) % np;
+		c[kk]=sum;
+	}
+}