mercator

Getting pixel coordinated from google static maps

由 牧云@^-^@ 提交于 2020-02-08 06:58:45
问题 I want to find out the pixels coordinates of a lat/lng on an static map. For example i've downloaded an image from: Link to Image What I want is from a lat/lng long to be able to map that latlng to pixel coordinates. I've searched a bit and found that mercator projection can solve my problem. However I could not find any proper way of doing it. Can somebody please help me. Also I've zoomed to 9 when as shown in the URL . 回答1: Converting Lat/Lon to pixel for a google static map is very useful

Getting pixel coordinated from google static maps

由 我怕爱的太早我们不能终老 提交于 2020-02-08 06:58:12
问题 I want to find out the pixels coordinates of a lat/lng on an static map. For example i've downloaded an image from: Link to Image What I want is from a lat/lng long to be able to map that latlng to pixel coordinates. I've searched a bit and found that mercator projection can solve my problem. However I could not find any proper way of doing it. Can somebody please help me. Also I've zoomed to 9 when as shown in the URL . 回答1: Converting Lat/Lon to pixel for a google static map is very useful

d3.js mercator projection to NYC map

由 一笑奈何 提交于 2019-12-22 20:48:19
问题 I am making a map of the boroughs in NYC and I can't seem to get the projection right: the only thing I get is a tiny map. I tried recreating this example, which only made the console go crazy with errors, I suspect because there was something off about the equation. When I was trying to get albers to work, I tried out the answer to this question, and still I could not get the map to work. With 960/500 height and width, I used: var projection = d3.geo.albers().center([40.71, 73.98]).parallels

D3 mercator function NaN

由 纵然是瞬间 提交于 2019-12-22 06:29:10
问题 I'm not too familiar with the D3 mercator projection function, and I'm getting some unexpected results. I'd like to project the following latitude and longitude (somewhere in Mexico): var geo = [19, -99] I define my mercator projection using d3 var projection = d3.geo.mercator(); projection(geo) > [529.7418836818384, NaN] which is a point obviously not on a map. What exactly am I doing wrong? Thanks! 回答1: Javascript has it's lat and long round the opposite way to the rest of the world, so

D3 mercator function NaN

由 冷暖自知 提交于 2019-12-22 06:29:04
问题 I'm not too familiar with the D3 mercator projection function, and I'm getting some unexpected results. I'd like to project the following latitude and longitude (somewhere in Mexico): var geo = [19, -99] I define my mercator projection using d3 var projection = d3.geo.mercator(); projection(geo) > [529.7418836818384, NaN] which is a point obviously not on a map. What exactly am I doing wrong? Thanks! 回答1: Javascript has it's lat and long round the opposite way to the rest of the world, so

How to convert radius in metres to pixels in mapbox leaflet?

由 可紊 提交于 2019-12-12 09:44:29
问题 I am working on an application where I am trying to run some algorithms on a map and calculate coords but they are slightly off because I am running the calculations on latitude and longitudes and the final results are getting distorted. Now I am trying to convert all coordinates to EPSG3857 Web Mercator coordinates like so: var crs = L.CRS.EPSG3857; var zoom = terrainAnalysisMap.getZoom(); markerToPoint = crs.latLngToPoint(marker.getLatLng(), zoom); markerOnRadiusToPoint = crs.latLngToPoint

Calculating Mercator d3 scaling to match Leaflet zoom level

由 三世轮回 提交于 2019-12-11 05:28:00
问题 Given a Leaflet zoom level (0..22), how would I calculate D3 scaling value for geoMercator projection? At zoom=0, the whole world fits within a single tile (256x256). In tiles, the world size is 2^zoom x 2^zoom tiles. 回答1: For comparison with d3 scales for Mercator maps: A mercator map uses this formula: var point = [x, Math.log(Math.tan(Math.PI / 4 + y / 2))]; The scale factor in a d3 map essentially applies the following transform: point[0] = point[0] * k; point[1] = -point[1] * k; The

d3.js mercator projection to NYC map

由 我的未来我决定 提交于 2019-12-06 05:59:06
I am making a map of the boroughs in NYC and I can't seem to get the projection right: the only thing I get is a tiny map. I tried recreating this example, which only made the console go crazy with errors, I suspect because there was something off about the equation. When I was trying to get albers to work, I tried out the answer to this question, and still I could not get the map to work. With 960/500 height and width, I used: var projection = d3.geo.albers().center([40.71, 73.98]).parallels([29.5, 45.5]).scale(10000).translate([(width) / 2, (height)/2]); Right now, I am using a transverse

How to convert radius in metres to pixels in mapbox leaflet?

由 冷暖自知 提交于 2019-12-05 14:57:47
I am working on an application where I am trying to run some algorithms on a map and calculate coords but they are slightly off because I am running the calculations on latitude and longitudes and the final results are getting distorted. Now I am trying to convert all coordinates to EPSG3857 Web Mercator coordinates like so: var crs = L.CRS.EPSG3857; var zoom = terrainAnalysisMap.getZoom(); markerToPoint = crs.latLngToPoint(marker.getLatLng(), zoom); markerOnRadiusToPoint = crs.latLngToPoint(markerOnRadius.getLatLng(), zoom); Now I also have a radius which I will have to convert from metres to

D3 mercator function NaN

由 戏子无情 提交于 2019-12-05 11:26:35
I'm not too familiar with the D3 mercator projection function, and I'm getting some unexpected results. I'd like to project the following latitude and longitude (somewhere in Mexico): var geo = [19, -99] I define my mercator projection using d3 var projection = d3.geo.mercator(); projection(geo) > [529.7418836818384, NaN] which is a point obviously not on a map. What exactly am I doing wrong? Thanks! Javascript has it's lat and long round the opposite way to the rest of the world, so what you've given D3 is a longditue of 19 and a latitude of -99. Obviously there is no latitude of -99 hence
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