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Projection questions

#1

My map will always be in decimal degrees, and all the shape files will be in decimal degrees as well. However, I want to be able to project the map in mercator projection.

  1. Do I have to set every layer in the app to the projection one by one, or is there a way to set all of them at once?
  2. After I change the projection, does adding points/lines/polygons change at all? I’ll always be plotting them manually given a lat/long in decimal degrees.
  3. I noticed there’s a builtin spherical mercator projection. The projection I want is the standard Mercator projection, which is having left to right -180 to +180 degrees. What would be the correct way to set this projection on a layer?

Thanks!

#2

Hi Dan,

  1. You have to set the projection one by one.
  2. After you set the projection to layer, you still need add the shapes under their original projection. If the new shape is under decimal degree, please convert it back to original one then add them to layer.
  3. If you don’t want to use our default projection, please query that in http://spatialreference.org/ to get the proj4 string and use it.

Regards,

Ethan