diff options
| author | Mistivia <i@mistivia.com> | 2025-11-02 15:27:18 +0800 |
|---|---|---|
| committer | Mistivia <i@mistivia.com> | 2025-11-02 15:27:18 +0800 |
| commit | e9c24f4af7ed56760f6db7941827d09f6db9020b (patch) | |
| tree | 62128c43b883ce5e3148113350978755779bb5de /teleirc/matterbridge/vendor/github.com/av-elier/go-decimal-to-rational/frac.go | |
| parent | 58d5e7cfda4781d8a57ec52aefd02983835c301a (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.go | 44 |
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 +} |
