find-stone-beer / files / coord-round.go
coord-round.go
| 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "math" |
| 6 | "strings" |
| 7 | |
| 8 | "github.com/jftuga/geodist" |
| 9 | ) |
| 10 | |
| 11 | type ImperialDistance struct { |
| 12 | Miles float64 |
| 13 | } |
| 14 | |
| 15 | func (d ImperialDistance) GetFeet() float64 { |
| 16 | feet := d.Miles * 5280 |
| 17 | return feet |
| 18 | } |
| 19 | func (d ImperialDistance) GetInches() float64 { |
| 20 | inches := d.GetFeet() * 12 |
| 21 | return inches |
| 22 | } |
| 23 | func (d ImperialDistance) ToString() string { |
| 24 | miles := Round(d.Miles, 2) |
| 25 | feet := Round(d.GetFeet(), 2) |
| 26 | inches := Round(d.GetInches(), 2) |
| 27 | |
| 28 | if miles > 1 { |
| 29 | return fmt.Sprintf("%.2fmi", miles) |
| 30 | } |
| 31 | |
| 32 | if feet > 1 { |
| 33 | return fmt.Sprintf("%.2fft", feet) |
| 34 | } |
| 35 | |
| 36 | return fmt.Sprintf("%.2fin", inches) |
| 37 | } |
| 38 | |
| 39 | func GetPrecisionDistance(coord geodist.Coord) (ImperialDistance, error) { |
| 40 | latDelta := getDelta(coord.Lat) |
| 41 | minLat := coord.Lat - latDelta |
| 42 | maxLat := coord.Lat + latDelta |
| 43 | |
| 44 | lonDelta := getDelta(coord.Lon) |
| 45 | minLon := coord.Lon - lonDelta |
| 46 | maxLon := coord.Lon + lonDelta |
| 47 | |
| 48 | minCoord := geodist.Coord{Lat: minLat, Lon: minLon} |
| 49 | maxCoord := geodist.Coord{Lat: maxLat, Lon: maxLon} |
| 50 | distMiles, _, err := geodist.VincentyDistance(minCoord, maxCoord) |
| 51 | if err != nil { |
| 52 | return ImperialDistance{}, err |
| 53 | } |
| 54 | id := ImperialDistance{Miles: distMiles} |
| 55 | return id, nil |
| 56 | } |
| 57 | |
| 58 | func getDelta(f float64) float64 { |
| 59 | text := fmt.Sprintf("%g", f) |
| 60 | if !strings.Contains(text, ".") { |
| 61 | return 1 |
| 62 | } |
| 63 | afterDecimal := strings.Split(text, ".")[1] |
| 64 | afterDecimal = strings.TrimRight(afterDecimal, "0") |
| 65 | decimals := len(afterDecimal) |
| 66 | delta := math.Pow(10, -float64(decimals)) |
| 67 | return delta |
| 68 | } |
| 69 | |
| 70 | func RoundCoord(c geodist.Coord, id ImperialDistance) (geodist.Coord, error) { |
| 71 | var lastRoundedCoord geodist.Coord |
| 72 | for decimalPlaces := 1; decimalPlaces < 7; decimalPlaces++ { |
| 73 | lat := Round(c.Lat, decimalPlaces) |
| 74 | lon := Round(c.Lon, decimalPlaces) |
| 75 | roundedCoord := geodist.Coord{Lat: lat, Lon: lon} |
| 76 | roundedId, err := GetPrecisionDistance(roundedCoord) |
| 77 | if err != nil { |
| 78 | return geodist.Coord{}, err |
| 79 | } |
| 80 | if roundedId.Miles < id.Miles { |
| 81 | return lastRoundedCoord, nil |
| 82 | } |
| 83 | lastRoundedCoord = roundedCoord |
| 84 | } |
| 85 | |
| 86 | return geodist.Coord{}, fmt.Errorf("could not round coord: %v", c) |
| 87 | } |
| 88 | |
| 89 | func Round(f float64, places int) float64 { |
| 90 | shift := math.Pow(10, float64(places)) |
| 91 | return math.Round(f*shift) / shift |
| 92 | } |