From a225f49209dacc21dc70d579afb6d5aea04409b9 Mon Sep 17 00:00:00 2001
From: starainrt <i@b612.me>
Date: Fri, 13 Aug 2021 14:26:08 +0800
Subject: [PATCH] important bug fix:infinite recursion occurs on constellation
 calculation

---
 basic/star.go      | 11 ++++-------
 basic/star_test.go |  9 ++++++++-
 tools/math.go      |  7 ++-----
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/basic/star.go b/basic/star.go
index d553cab..9c7ef54 100644
--- a/basic/star.go
+++ b/basic/star.go
@@ -141,17 +141,14 @@ func init() {
 	CstLists["VIR"] = []cst{cst{174.35052458333, -0.6916979}, cst{174.36568791667, 10.3082914}, cst{179.60373458333, 10.3040485}, cst{179.60453541667, 13.3040485}, cst{194.0620275, 13.3225126}, cst{194.05906625, 14.3225088}, cst{204.02893041667, 14.3604937}, cst{204.06384875, 7.3605771}, cst{227.78148625, 7.5253930}, cst{227.85301208333, -0.4742887}, cst{221.6030925, -0.5269387}, cst{221.66710791667, -8.5266848}, cst{215.40850625, -8.5731344}, cst{215.51309125, -22.5727749}, cst{194.16687, -22.6773415}, cst{194.1330525, -11.6773882}, cst{179.09676, -11.6957970}, cst{179.09860625, -6.6957974}, cst{174.34229875, -6.6916924}}
 	CstLists["VOL"] = []cst{cst{98.93724875, -64.1070251}, cst{98.454422916667, -70.1041336}, cst{97.770709583333, -75.1000366}, cst{114.21470375, -75.2899170}, cst{135.24368708333, -75.4954681}, cst{136.09472708333, -64.4990387}, cst{102.70331375, -64.1518784}}
 	CstLists["VUL"] = []cst{cst{284.33913291667, 21.2478352}, cst{284.27716208333, 25.6641407}, cst{290.16131375, 25.7325745}, cst{290.13264625, 27.7324085}, cst{296.27220125, 27.8011742}, cst{296.25094375, 29.3010578}, cst{315.07258375, 29.4871387}, cst{315.08391458333, 28.4871883}, cst{322.62016375, 28.5480537}, cst{322.66201958333, 24.0482101}, cst{320.15170041667, 24.0289364}, cst{320.18840875, 20.0290813}, cst{317.17878291667, 20.0046406}, cst{309.907665, 19.9399967}, cst{309.89693708333, 20.9399471}, cst{305.13404875, 20.8936996}, cst{305.12540875, 21.6436558}, cst{298.860255, 21.5787334}, cst{298.88568875, 19.4955387}, cst{290.12128791667, 19.3982983}, cst{290.09631125, 21.3148155}}
-
 	change := []string{"PSC", "TUC", "PHE", "SCL", "CET", "PEG", "AND", "CAS", "CEP"}
 	for _, v := range change {
 		for k, v2 := range CstLists[v] {
 			if v2.RA < 270 {
 				CstLists[v][k].RA = v2.RA + 360
 			}
-
 		}
 	}
-
 }
 
 //选定 RA=277.5 DEC=-40
@@ -192,11 +189,11 @@ func isCross(a, b, c, d cst) bool {
 func IsXZ(ra, dec, jde float64) string {
 	var nra, ndec float64
 	nra = ra
-	if ra > 360 {
-		nra = ra - 360
+	if ra >= 360 {
+		nra -= 360
 	}
 	nra, ndec = ZuoBiaoSuiCha(nra, dec, jde, 2451545.0)
-	if ra > 360 && nra < 300 {
+	if ra >= 360 && nra < 270 {
 		nra += 360
 	}
 	for k, v := range CstLists {
@@ -221,7 +218,7 @@ func IsXZ(ra, dec, jde float64) string {
 			return k
 		}
 	}
-	if nra <= 360 {
+	if nra <= 270 {
 		ra = ra + 360
 		return IsXZ(ra, dec, jde)
 	}
diff --git a/basic/star_test.go b/basic/star_test.go
index 9a4debb..9264eff 100644
--- a/basic/star_test.go
+++ b/basic/star_test.go
@@ -1,9 +1,16 @@
 package basic
 
 import (
+	"fmt"
 	"testing"
 )
 
 func Test_Isxz(t *testing.T) {
-
+	now := GetNowJDE()
+	for i := 0.00; i <= 360.00; i+=0.5 {
+		for j := -90.00; j <= 90.00; j+=0.5 {
+			fmt.Println(i, j)
+			fmt.Println(WhichCst(float64(i), float64(j), now))
+		}
+	}
 }
diff --git a/tools/math.go b/tools/math.go
index 1a28de2..ca91d05 100644
--- a/tools/math.go
+++ b/tools/math.go
@@ -1,9 +1,7 @@
 package tools
 
 import (
-	"fmt"
 	"math"
-	"strconv"
 )
 
 func Sin(x float64) float64 {
@@ -31,9 +29,8 @@ func ArcTan(x float64) float64 {
 }
 
 func FloatRound(f float64, n int) float64 {
-	format := "%." + strconv.Itoa(n) + "f"
-	res, _ := strconv.ParseFloat(fmt.Sprintf(format, f), 64)
-	return res
+	p := math.Pow10(n)
+	return math.Floor(f*p+0.5) / p
 }
 
 func Limit360(x float64) float64 {