Filter a layer based on a shp file

Hello,

I have raster grid layer which I want to filter for specific areas using a shp file. That is to recreate the original raster layer but filtered for certain polygons using a shp file. Is that possible at all? 

Many thanks

Best Answers

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,883
    Answer ✓
    Hello,

    To filter your raster grid using a shapefile:
    1. Load both your raster grid file and shapefile
    2. In the Overlay Control Center, right-click on your shapefile layer and choose SELECT - Select all Features in Selected Layer(s) with the Digitizer Tool
    3. File | Export | Export Elevation Grid Format
    4. Choose your output format from the list
    5. On the Export Options screen, choose the Export Bounds tab
    6. Select the option: "Crop to Selected Area Feature(s)
    7. Fill in any other options you want, and click OK.
    Cheers,

    Bob
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,883
    edited May 2016 Answer ✓
    Zaid said:

    1- What happens if there is more than one raster grid file loaded?
    2- Can Global Mapper calculate the area size of the shp file?


    1. All of the loaded grid data will be exported to the file you choose.  If you want to prevent some layers from being exported, you should hide them before starting the export.
    2. Yes. In the Control Center, select the shapefile layer and click the Metadata... button.  Towards the bottom of the list of data, you will see COVERED_AREA, which is the total area.  If you want to see the area for each area feature, select all of the area features in the Digitizer, right-click and choose Analysis/Measurement | MEASURE - Display Feature Measurements.  You can export the measurements to a CSV file or have them copied to the clipboard.
    Cheers,

    Bob

Answers

  • ZaidZaid Posts: 2
    Many thanks Bob. 

    I managed to follow your steps and it seems all good. Two more questions please:

    1- What happens if there is more than one raster grid file loaded?
    2- Can Global Mapper calculate the area size of the shp file?

    Cheers
    Zaid
     


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