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I wonder why some .csv files when imported (with long and lat) can not set a proper CRS system and other do (CRS undefined). For example:

  1. If I export my data in csv with Microsoft Excel it does not set the CRS and can not be fixed.
  2. when I export with Google Sheets it does work.

What is the problem in this case? I am trying to export data with pandas python but can not figure out this problem? I am using QGIS, 2.12.1-Lyon, on MAC.

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CSV files do not contain any CRS information, just coordinates.

In QGIS, take a look at Settings -> Options -> CRS tab. Under CRS for new Layers you can choose Prompt for CRS. It might be set to a default CRS of WGS84 using degrees, and if the coordinates exceed +/-180/90, the CRS will be set to undefined.

Apart from that, QGIS on MAC has some problems with CR-LF in CSV files, see QGIS won't read table columns in CSV import on Mac OS and https://stackoverflow.com/questions/22052168/excel-saves-tab-delimited-files-without-newline-unix-mac-os-x

  • Just to make clear, the CRS you are working with is defined as above. Any crs information that comes with any dataset, is used to reproject/transform to the base CRS defined as above. Is a good practice to use formats that embedded this kind of information, because most of the times there are special considerations when moving from one crs to another, and the program uses that information to apply the correct transformation method. – nickves Apr 12 '16 at 11:50

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