diff options
Diffstat (limited to 'vendor/github.com/ncruces/julianday')
| -rw-r--r-- | vendor/github.com/ncruces/julianday/.gitignore | 15 | ||||
| -rw-r--r-- | vendor/github.com/ncruces/julianday/LICENSE | 21 | ||||
| -rw-r--r-- | vendor/github.com/ncruces/julianday/README.md | 9 | ||||
| -rw-r--r-- | vendor/github.com/ncruces/julianday/julianday.go | 124 |
4 files changed, 169 insertions, 0 deletions
diff --git a/vendor/github.com/ncruces/julianday/.gitignore b/vendor/github.com/ncruces/julianday/.gitignore new file mode 100644 index 000000000..66fd13c90 --- /dev/null +++ b/vendor/github.com/ncruces/julianday/.gitignore @@ -0,0 +1,15 @@ +# Binaries for programs and plugins +*.exe +*.exe~ +*.dll +*.so +*.dylib + +# Test binary, built with `go test -c` +*.test + +# Output of the go coverage tool, specifically when used with LiteIDE +*.out + +# Dependency directories (remove the comment below to include it) +# vendor/ diff --git a/vendor/github.com/ncruces/julianday/LICENSE b/vendor/github.com/ncruces/julianday/LICENSE new file mode 100644 index 000000000..7f0f5534c --- /dev/null +++ b/vendor/github.com/ncruces/julianday/LICENSE @@ -0,0 +1,21 @@ +MIT License + +Copyright (c) 2022 Nuno Cruces + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/vendor/github.com/ncruces/julianday/README.md b/vendor/github.com/ncruces/julianday/README.md new file mode 100644 index 000000000..828ae5749 --- /dev/null +++ b/vendor/github.com/ncruces/julianday/README.md @@ -0,0 +1,9 @@ +# Julian Day calculator + +[](https://pkg.go.dev/github.com/ncruces/julianday) +[](https://goreportcard.com/report/github.com/ncruces/julianday) +[](https://raw.githack.com/wiki/ncruces/julianday/coverage.html) + +https://en.wikipedia.org/wiki/Julian_day + +Compatible with [SQLite](https://www.sqlite.org/lang_datefunc.html). diff --git a/vendor/github.com/ncruces/julianday/julianday.go b/vendor/github.com/ncruces/julianday/julianday.go new file mode 100644 index 000000000..d7d0e1960 --- /dev/null +++ b/vendor/github.com/ncruces/julianday/julianday.go @@ -0,0 +1,124 @@ +// Package julianday provides Time to Julian day conversions. +package julianday + +import ( + "bytes" + "errors" + "math" + "strconv" + "time" +) + +const secs_per_day = 86_400 +const nsec_per_sec = 1_000_000_000 +const nsec_per_day = nsec_per_sec * secs_per_day +const epoch_days = 2_440_587 +const epoch_secs = secs_per_day / 2 + +func jd(t time.Time) (day, nsec int64) { + sec := t.Unix() + // guaranteed not to overflow + day, sec = sec/secs_per_day+epoch_days, sec%secs_per_day+epoch_secs + return day, sec*nsec_per_sec + int64(t.Nanosecond()) +} + +// Date returns the Julian day number for t, +// and the nanosecond offset within that day, +// in the range [0, 86399999999999]. +func Date(t time.Time) (day, nsec int64) { + day, nsec = jd(t) + switch { + case nsec < 0: + day -= 1 + nsec += nsec_per_day + case nsec >= nsec_per_day: + day += 1 + nsec -= nsec_per_day + } + return day, nsec +} + +// Float returns the Julian date for t as a float64. +// +// In the XXI century, this has submillisecond precision. +func Float(t time.Time) float64 { + day, nsec := jd(t) + // converting day and nsec to float64 is exact + return float64(day) + float64(nsec)/nsec_per_day +} + +// Format returns the Julian date for t as a string. +// +// This has nanosecond precision. +func Format(t time.Time) string { + var buf [32]byte + return string(AppendFormat(buf[:0], t)) +} + +// AppendFormat is like Format but appends the textual representation to dst +// and returns the extended buffer. +func AppendFormat(dst []byte, t time.Time) []byte { + day, nsec := Date(t) + if day < 0 && nsec != 0 { + dst = append(dst, '-') + day = ^day + nsec = nsec_per_day - nsec + } + var buf [20]byte + dst = strconv.AppendInt(dst, day, 10) + frac := strconv.AppendFloat(buf[:0], float64(nsec)/nsec_per_day, 'f', 15, 64) + return append(dst, bytes.TrimRight(frac[1:], ".0")...) +} + +// Time returns the UTC Time corresponding to the Julian day number +// and nanosecond offset within that day. +// Not all day values have a corresponding time value. +func Time(day, nsec int64) time.Time { + return time.Unix((day-epoch_days)*secs_per_day-epoch_secs, nsec).UTC() +} + +// FloatTime returns the UTC Time corresponding to a Julian date. +// Not all date values have a corresponding time value. +// +// In the XXI century, this has submillisecond precision. +func FloatTime(date float64) time.Time { + day, frac := math.Modf(date) + nsec := math.Floor(frac * nsec_per_day) + return Time(int64(day), int64(nsec)) +} + +// Parse parses a formatted Julian date and returns the UTC Time it represents. +// +// This has nanosecond precision. +func Parse(s string) (time.Time, error) { + digits := 0 + dot := len(s) + for i, b := range []byte(s) { + if '0' <= b && b <= '9' { + digits++ + continue + } + if b == '.' && i < dot { + dot = i + continue + } + if (b == '+' || b == '-') && i == 0 { + continue + } + return time.Time{}, errors.New("julianday: invalid syntax") + } + if digits == 0 { + return time.Time{}, errors.New("julianday: invalid syntax") + } + + day, err := strconv.ParseInt(s[:dot], 10, 64) + if err != nil && dot > 0 { + return time.Time{}, errors.New("julianday: value out of range") + } + frac, _ := strconv.ParseFloat(s[dot:], 64) + nsec := int64(math.Round(frac * nsec_per_day)) + if s[0] == '-' { + nsec = -nsec + } + return Time(day, nsec), nil +} |