[GIS] Plotting latitude on (Mercator projection) SVG representing country map

coordinateslatitude longitudesvg

I want to convert (google sourced) longitude and latitude coordinates to x and y to place points on a SVG map

I can get the longitude converted to X but I can't nail latitude.

http://jsfiddle.net/chrisloughnane/an3BZ/17/

red dots = place holders
green dot = calculated position from longitude/latitude

I have read so much about Mercator projections and other projection system API's I am now completely confused. I also followed Proj4JS library threads but couldn't find an example that was close to my task.

I attempted to emulate @Raphael Wichmann and @betamax solution, unfortunately I got something wrong.

Could someone have a look at my jsfiddle and see if it's an obvious mistake?

The second test function secondconvert(latitude, longitude) (bottom of javascript pane) provides me with a reasonably accurate x coordinate i.e. if I manually enter the y coordinate b.ylat change to 265 it covers my left red dot place holder nearly perfectly.

I think I'm close.

Note: the longitude/latitude bounds I used for my SVG map are best guesstimates, worked surprisingly well for the longitude calculation.

Original SVG from here.

Best Answer

This question was answered by @acraig5075 here.

After correcting my mistake and adjusting southern latitude I get: Fixed link: http://jsfiddle.net/an3BZ/145/

Related Solutions

Shapefile to SVG with ArcMap – Retaining Country Attributes

I created those maps, so I can describe the process I used. There's probably a better way to do it, but here's how it works for me:

In ArcMap, give each state its own layer. I use layer ID's from the source layer attributes table and then a bit of ArcMap Python:

import arcgisscripting
gp = arcgisscripting.create()
gp.MakeFeatureLayer_management('ne_110m_admin_0_countries','AF','"ABBREV" = \'Afg.\'')
gp.MakeFeatureLayer_management('ne_110m_admin_0_countries','AO', '"ABBREV" = \'Ang.\'')
gp.MakeFeatureLayer_management('ne_110m_admin_0_countries','AL', '"ABBREV" = \'Alb.\'')
...etc...

This creates a new layer for each state named with that stat's two-letter ISO code.

I export from ArcMap as Adobe Illustrator. In Illustrator, the layers are preserved and named as they were in ArcMap. In Illustrator I size up the shapes appropriately and do some fine-tuning on the styles. Then export as SVG.
Run this perl script to convert SVG file to Raphael.js friendly json: https://gist.github.com/2655111

And that's that!

[GIS] How to make SVG Stabius-Werner projection

you could use the program MicroCAM (free), export to hpgl Plot-File and afterwards import into Inkscape. I have uploaded an example here: http://commons.wikimedia.org/wiki/File:Stabwerner.svg

Download-Link for MicroCAM: http://www.csiss.org/map-projections/microcam/

additional info: As http://de.wikipedia.org/wiki/Stab-Wernersche_Projektion explains, the Stabius-Werner is a Bonne-Projection with a standard-parallel 90 degree north.

there is a bonne90.cam example file included with the microCam distribution

update: you can download also this pdf-map http://www.csiss.org/map-projections/Pseudoconic/Stab_Werner.pdf and import into inkscape

update2: if a high-resolution, high-quality raster map,which you can import into your svg-file, also fits your needs, I recommend the free program g.projector, which you can download here: http://www.giss.nasa.gov/tools/gprojector/

Related Question

[GIS] Compute the latitude of a center of mercator projection