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/ansi/recipes/caldat.c
+++ b/lib/nr/ansi/recipes/caldat.c
@@ -0,0 +1,28 @@
+
+#include <math.h>
+#define IGREG 2299161
+
+void caldat(long julian, int *mm, int *id, int *iyyy)
+{
+	long ja,jalpha,jb,jc,jd,je;
+
+	if (julian >= IGREG) {
+		jalpha=(long)(((double) (julian-1867216)-0.25)/36524.25);
+		ja=julian+1+jalpha-(long) (0.25*jalpha);
+	} else if (julian < 0) {
+		ja=julian+36525*(1-julian/36525);
+	} else
+		ja=julian;
+	jb=ja+1524;
+	jc=(long)(6680.0+((double) (jb-2439870)-122.1)/365.25);
+	jd=(long)(365*jc+(0.25*jc));
+	je=(long)((jb-jd)/30.6001);
+	*id=jb-jd-(long) (30.6001*je);
+	*mm=je-1;
+	if (*mm > 12) *mm -= 12;
+	*iyyy=jc-4715;
+	if (*mm > 2) --(*iyyy);
+	if (*iyyy <= 0) --(*iyyy);
+	if (julian < 0) *iyyy -= 100*(1-julian/36525);
+}
+#undef IGREG