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authorMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
committerMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
commite9c24f4af7ed56760f6db7941827d09f6db9020b (patch)
tree62128c43b883ce5e3148113350978755779bb5de /teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go
parent58d5e7cfda4781d8a57ec52aefd02983835c301a (diff)
add matterbridge
Diffstat (limited to 'teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go')
-rw-r--r--teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go44
1 files changed, 44 insertions, 0 deletions
diff --git a/teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go b/teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go
new file mode 100644
index 0000000..a20f853
--- /dev/null
+++ b/teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go
@@ -0,0 +1,44 @@
+package dectofrac
+
+import (
+ "math"
+ "math/big"
+)
+
+// MaxIterations is some sane limit of iterations for precision mode
+const MaxIterations = 5000
+
+// NewRatI returns rational from decimal
+// using `iterations` number of iterations in Continued Fraction algorythm
+func NewRatI(val float64, iterations int64) *big.Rat {
+ return NewRat(val, iterations, 0)
+}
+
+// NewRatP returns rational from decimal
+// by going as mush iterations, until next fraction is less than `stepPrecision`
+func NewRatP(val float64, stepPrecision float64) *big.Rat {
+ return NewRat(val, MaxIterations, stepPrecision)
+}
+
+func NewRat(val float64, iterations int64, stepPrecision float64) *big.Rat {
+ a0 := int64(math.Floor(val))
+ x0 := val - float64(a0)
+ rat := cf(x0, 1, iterations, stepPrecision)
+ return rat.Add(rat, new(big.Rat).SetInt64(a0))
+}
+
+func cf(xi float64, i int64, limit int64, stepPrecision float64) *big.Rat {
+ if i >= limit || xi <= stepPrecision {
+ return big.NewRat(0, 1)
+ }
+
+ inverted := 1 / xi
+ aj := int64(math.Floor(inverted))
+ xj := inverted - float64(aj)
+ ratAJ := new(big.Rat).SetInt64(aj)
+ ratNext := cf(xj, i+1, limit, stepPrecision)
+ res := ratAJ.Add(ratAJ, ratNext)
+ res = res.Inv(res)
+
+ return res
+}