Global Mapper v25.0

Calculate Attributes or Import Attributes from Excel

rreed
rreed Global Mapper UserTrusted User
edited May 2014 in Technical Support
Hello,

I have many lines of many different lengths. Is there a way to have GM calculate an area based on a common width that is assigned to all of the lines? Alternately, if I copy the lines to the clipboard, paste into Excel, and perform math functions in Excel, can I create a new attribute field in GM and then paste the computed values into the newly created attribute field for all of my lines (I would want to paste all of the attributes at once, rather than one at a time)?

Thanks.

Russ

Comments

  • global_mapper
    global_mapper Administrator
    edited May 2014
    Russ,

    You could do a table join from a CSV file saved from Excel, but there is a much easier method for something like this. Once you have the length attribute, just right-click on the layer in the Control Center and select the CALC ATTR option, then create a new attribute that is your length attribute multiplied by whatever width you need to get the enclosed area. In the near future we also plan to add free-form equation support when calculating attributes.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • rreed
    rreed Global Mapper User Trusted User
    edited May 2014
    Mike,

    Thanks for such a quick response (as always!). I follow-up question to this issue is that GM seems to store the units (e.g. ft) in the attribute data field. When I export the line entities as a shape file, or copy/paste them into Excel, the measured attribute for length imports into other programs with the units in the same field/cell. This is problematic in that other programs don't recognize the imported lenghts as values - they are seen as text. I can use Excel to strip of the units component, but I don't have that luxury in other applications. Further, as calculations are performed on the line segments, the units change, e.g. from ft to ft2 to acres.

    Can I change a global setting in GM to not include the units?

    Thanks.

    Russ

    Russ,

    You could do a table join from a CSV file saved from Excel, but there is a much easier method for something like this. Once you have the length attribute, just right-click on the layer in the Control Center and select the CALC ATTR option, then create a new attribute that is your length attribute multiplied by whatever width you need to get the enclosed area. In the near future we also plan to add free-form equation support when calculating attributes.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • global_mapper
    global_mapper Administrator
    edited May 2014
    Russ,

    Yes, if you activate the Measure Tool (ruler on toolbar), then right-click on the map there is an option there to disable appending units to the measure values. You can also choose to force the units to stay in the base or larger units, so all would be meters or feet for instance, rather than switching to kilometers or miles for large distances.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation