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javascript coordinate conversions between 900913(3857) - 4326(lat lon)
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var degrees2meters = function(lon,lat) { | |
var x = lon * 20037508.34 / 180; | |
var y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180); | |
y = y * 20037508.34 / 180; | |
return [x, y] | |
} | |
//test | |
lon= -77.035974 | |
lat = 38.898717 | |
console.log(degrees2meters(lon,lat)) | |
// should result in: -8575605.398444, 4707174.018280 |
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var meters2degress = function(x,y) { | |
var lon = x * 180 / 20037508.34 ; | |
//thanks magichim @ github for the correction | |
var lat = Math.atan(Math.exp(y * Math.PI / 20037508.34)) * 360 / Math.PI - 90; | |
return [lon, lat] | |
} | |
//test | |
x= -8575605.398444 | |
y = 4707174.018280 | |
console.log(meters2degress(x,y)) | |
//should result in: -77.035974, 38.898717 |
you saved my life, thank you
you saved my life, thank you
I'm glad that I could help. But don't forget that it is just to translate 4326 to 900913(3857) and visa versa. This calculation cannot be used for length measurements because of high error margin.
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Based on geometric knowledge and you can see the fixes happened in the past by contribution of commenters.