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Questions tagged [map-projections]

A map-projection transforms the coordinates of the spherical earth to a flat map in cartesian (x,y) space.

A map-projection transforms the coordinates of the spherical earth, usually given in degrees (latitude, longitude), to a flat cartesian (x,y) space.
There is no perfect projection, it can be proved that each projection has a drawback, one have minor others major ones.

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Obtaining coordinates in projected map using Cartopy

I'm trying to obtain the coordinates of the features of a map using Cartopy but I would like to obtain the map projected coordinates instead of the data from the original projection. For instance: import matplotlib.pyplot as plt import cartopy.crs…
kikocorreoso
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R: ggplot2 legend disappears when changing colour scheme

Inspired by this post, I tried plotting a world map using Robinson projection and adding coloured dots to the map. Reprojecting the map and points works fine, but, for some reason I don't understand, I can't change the colour scheme of the dots and…
Lukas
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Other projections in Google Maps API?

I'm plotting data using lat/lons with Google Maps API. However, some of my data is at high latitude, and it isn't plotted because Google Maps uses a Mercator projection which cuts off at 85 degrees. Is there any way around this? Here's my current…
Michael Erb
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Show geojson featureCollection with Leaflet

with QGIS I´ve exported a polygon layer as geojson which I´d like to publish with leaflet. This is how the geojson looks like [exluded due to SO character limits]: https://gist.github.com/t-book/88806d12d7f05024b147715be82e6844 This is what I´ve…
Anatol
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Setting a custom projection using d3-geo-projection command line tool

I'm trying to use geoproject to set the projection on a geojson file. Specifically I'm trying to set the projection to BCalbers (http://spatialreference.org/ref/epsg/3005/) I see geoproject has a number of projections options i.e. geoproject…
brownshoes
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d3 fitSize gives NaN values

I want to make my d3 map fit to a svg container created with dynamic width and height attributes. It works so far by using the following code: var height = $("#map-container").height(), width = height * 0.9; var svg =…
Jan Seipel
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D3.js Map with Albers Projection: How to rotate it?

I'm building a map of the Philippines with d3.js and for a strange reason the map looks like rotated on the left, so that the country doesn't look how it really is. I've tried to modify the projection.rotate field but doesn't seems like is the…
Daniele Palumbo
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Armadillo projection in D3

I am trying to use the Armadillo projection in d3 (using the d3 projection plugin), but my map has rendering problems. The display is exactly the same than in the following bl.ocks project: http://bl.ocks.org/mortenjohs/4739921 (select Armadillo in…
Philippe V.
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Using three.js, how would you project a globe world to a map on the screen?

I am curious about the limits of three.js. The following question is asked mainly as a challenge, not because I actually need the specific knowledge/code right away. Say you have a game/simulation world model around a sphere geometry representing a…
Elias Hasle
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How to simulate "Projection Camera Mapping" of video on to a multiple BabylonJS Mesh?

Question: How to simulate "Projection Camera Mapping" of video on to a multiple BabylonJS Mesh? Breakdown: How would I project a standard 16:9 video onto multiple Babylon mesh (live code); as if, the camera was a projector and the mesh was an…
Armeen Moon
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project from Geographic WGS84 to Mercator in R - points not finite

I am running into some projection issues in R that I do not understand. I have downloaded the following global dataset: http://www.naturalearthdata.com/downloads/110m-physical-vectors/110m-land/ I then am creating maps using different projections to…
Leah Wasser
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How to get pixel coordinates as latlng from a jpg image

I have a map image as jpg format. I am trying to calculate latitude and longitude for each pixel. I have 3 points coordinate also pixel row and column. At first actually I used python utm library and calculated distance difference between two points…
Melih Çolpan
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Why is there distortion for the same two geoJSON features with different base maps?

When displaying two features, a polygon a (see geoJSON) and its minimum bounding rectangle b (see geoJSON), I get the following result when viewing from geojson.io: The minimum bounding rectangle around the polygon looks more like a parallelogram…
Kyle
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How does d3 projection scales work?

I have a simple question: What does it mean to set the scale of a d3 projection to 1 compared to, say, 150? What do these values actually translate to in plain English? I understand that it scales the projection up and down (duh), but according to…
durrrutti
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How can I plot non-rectangular 2D data using matplotlib?

I am working on a calculation in Python which calculates the physical properties of an object for angles in the range 0 < θ < π/2 and 0 < φ < π/2 (i.e. the first octant). To visualize the properties I am currently plotting them as color values on a…
Chris Mueller
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