jma

README

jma

Download helper for https://www.jma.go.jp/bosai/nowc and https://www.jma.go.jp/bosai/kaikotan, written in Go.

Usage

package main

import (
	"fmt"
	"github.com/tak0kada/jma"
	"time"
)

func main() {
	now, _ := time.Parse(time.RFC3339, "2021-09-05T13:32:38Z")

	g := jma.GeoCoordinate{33.737131, 137.226929}
	var zoom uint = 8

	if !g.IsValid() {
		fmt.Println("invalid geocoordinate %s. normalizing...")
		g = g.Normalize()
	}
	fmt.Printf("GeoCoordinate: %s\n", g) // => GeoCoordinate: {Lat: 33.737131, Lon: 137.226929}

	t := g.GetTile(zoom)
	fmt.Printf("Tile: %s\n", t) // => Tile: {Level: 8, X: 225, Y: 102}

	err := jma.DownloadImageTile(t, now, 0, "./tile.png")
	if err != nil {
		fmt.Println(err)
	}
	err = jma.DownloadImage(g, zoom, jma.Rect{600, 800}, now, 0, "./example.png")
	if err != nil {
		fmt.Printf(err.Error())
	}
}

Output

• tile.png

• example.png

Reference

• 高解像度降水ナウキャスト
• 降水ナウキャスト
• 地理院タイル
• タイルマップで緯度経度からタイルを求める: conversion formula between geocoordinate and tile

Documentation

Index

• func CalcCorner(tc TileCoordinate, height float64, width float64) (TileCoordinate, TileCoordinate)
• func ConcatImages(imgs [][]image.Image) image.Image
• func CropImage(img image.Image, center TileCoordinate, rect Rect) image.Image
• func DownloadImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration, ...) error
• func DownloadImageTile(tile Tile, now time.Time, duration time.Duration, filepath string) error
• func FetchBorderImage(gc GeoCoordinate, zoom uint, rect Rect) (image.Image, error)
• func FetchImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration) (image.Image, error)
• func FetchImageTile(tile Tile, now time.Time, duration time.Duration) (image.Image, error)
• func FetchJmaImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration) (image.Image, error)
• func FetchMapImage(gc GeoCoordinate, zoom uint, rect Rect, datatype string) (image.Image, error)
• func Overlay(bottom image.Image, middle image.Image, top image.Image) (image.Image, error)
• type GeoCoordinate
  • func (g GeoCoordinate) GetTile(zoom uint) Tile
  • func (g GeoCoordinate) GetTileCoordinate(zoom uint) TileCoordinate
  • func (g GeoCoordinate) IsValid() bool
  • func (g GeoCoordinate) Normalize() GeoCoordinate
  • func (g GeoCoordinate) String() string
• type Rect
• type Tile
  • func (t Tile) IsValid() bool
  • func (t Tile) String() string
  • func (t Tile) ToBorderMapURL(ext string) string
  • func (t Tile) ToJmaURL(now time.Time, duration time.Duration, ext string) (string, error)
  • func (t Tile) ToMapURL(datatype string, ext string) string
• type TileCoordinate
  • func (tc TileCoordinate) GetTile() Tile
  • func (tc TileCoordinate) IsValid() bool
  • func (tc TileCoordinate) String() string
  • func (tc TileCoordinate) ToGeoCoordinate() GeoCoordinate

Functions

func CalcCorner

func CalcCorner(tc TileCoordinate, height float64, width float64) (TileCoordinate, TileCoordinate)

func ConcatImages

func ConcatImages(imgs [][]image.Image) image.Image

func CropImage

func CropImage(img image.Image, center TileCoordinate, rect Rect) image.Image

func DownloadImage

func DownloadImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration, filepath string) error

func DownloadImageTile

func DownloadImageTile(tile Tile, now time.Time, duration time.Duration, filepath string) error

func FetchBorderImage

func FetchBorderImage(gc GeoCoordinate, zoom uint, rect Rect) (image.Image, error)

func FetchImage

func FetchImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration) (image.Image, error)

func FetchImageTile

func FetchImageTile(tile Tile, now time.Time, duration time.Duration) (image.Image, error)

func FetchJmaImage

func FetchJmaImage(gc GeoCoordinate, zoom uint, rect Rect, now time.Time, duration time.Duration) (image.Image, error)

func FetchMapImage

func FetchMapImage(gc GeoCoordinate, zoom uint, rect Rect, datatype string) (image.Image, error)

func Overlay

func Overlay(bottom image.Image, middle image.Image, top image.Image) (image.Image, error)

Types

type GeoCoordinate

type GeoCoordinate struct {
	Lat float64 `validate:"gte=-85.0511287798,lte=85.0511287798,required"`
	Lon float64 `validate:"required"`
}

func (GeoCoordinate) GetTile

func (g GeoCoordinate) GetTile(zoom uint) Tile

func (GeoCoordinate) GetTileCoordinate

func (g GeoCoordinate) GetTileCoordinate(zoom uint) TileCoordinate

func (GeoCoordinate) IsValid

func (g GeoCoordinate) IsValid() bool

func (GeoCoordinate) Normalize

func (g GeoCoordinate) Normalize() GeoCoordinate

func (GeoCoordinate) String

func (g GeoCoordinate) String() string

type Rect

type Rect struct {
	H uint // pixels
	W uint // pixels
}

type Tile

type Tile struct {
	Zoom uint `validate:"gte=0,lte=18,required"`
	X    uint `json:"tile_x" validate:"required"`
	Y    uint `json:"tile_y" validate:"required"`
}

For the definition of Tile struct, see: https://maps.gsi.go.jp/development/siyou.html#siyou-url .

func (Tile) IsValid

func (t Tile) IsValid() bool

func (Tile) String

func (t Tile) String() string

func (Tile) ToBorderMapURL

func (t Tile) ToBorderMapURL(ext string) string

func (Tile) ToJmaURL

func (t Tile) ToJmaURL(now time.Time, duration time.Duration, ext string) (string, error)

Japan Meteorological Agency(気象庁)

func (Tile) ToMapURL

func (t Tile) ToMapURL(datatype string, ext string) string

Geospatial Information Authority(国土地理院)

type TileCoordinate

type TileCoordinate struct {
	Zoom uint    `validate:"gte=0,lte=18,required"`
	X    float64 `json:"tilecoordinate_x" validate:"required"`
	Y    float64 `json:"tilecoordinate_y" validate:"required"`
}

func (TileCoordinate) GetTile

func (tc TileCoordinate) GetTile() Tile

func (TileCoordinate) IsValid

func (tc TileCoordinate) IsValid() bool

func (TileCoordinate) String

func (tc TileCoordinate) String() string

func (TileCoordinate) ToGeoCoordinate

func (tc TileCoordinate) ToGeoCoordinate() GeoCoordinate