Imported shapefile attributes contain wrong values

sphillipssphillips Posts: 52
Hi,

Can anyone explain why GM appears to change the attribute values of imported shapefiles? I've noticed this happening several times. For example, I'm importing contours (generated from running an Interpolation in ArcMap) but notice that the values are different e.g. 55 appears as 5.00000000000e+000 or 40 appears as 4.00000000000e+001.

Thanks,
Steve

Best Answers

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,681
    Answer ✓
    sphillips said:

    Can anyone explain why GM appears to change the attribute values of imported shapefiles? I've noticed this happening several times. For example, I'm importing contours (generated from running an Interpolation in ArcMap) but notice that the values are different e.g. 55 appears as 5.00000000000e+000 or 40 appears as 4.00000000000e+001.

    Hello,

    You don't indicate what version of Global Mapper you are using.  In Global Mapper 18.1, we added an option to convert shapefile attributes from scientific notation to conventional numeric values.  Open the Configuration dialog, and go to the General | Vector Formats page.  Put a check next to "Reformat Numeric Attribute Values Using Scientific Notation."

    Cheers,
    Bob
  • JeffH@BMGJeffH@BMG Global Mapper Developer Posts: 266
    Answer ✓


    One thing to be careful of when you're working in the Search Vector Data dialog: values that appear to be numeric may be sorted as text, such that , say, a value of "2.03e2" is sorted as being less than a value of "200", when 203 is clearly greater than 200. The  interpretation of attribute values when sorting  in the attribute table is governed  -- somewhat confusingly -- by a dropdown a few rows above the table headers in the "Search Criteria" group. To the right side, there's a dropdown labeled "as" with the choices "Text" and "Number". If you select "Number", then click on the attribute column header, you should find that the column sorts the values will sort correctly.

    Best regards,

    ~Jeff
    sphillips

Answers

  • sphillipssphillips Posts: 52
    Also I notice that some Attribute headings are renamed to ATTR_1, ATTR_2, ATTR_3 etc. Can this be avoided?
  • JeffH@BMGJeffH@BMG Global Mapper Developer Posts: 266Trusted User
    Hi Steve,

    If you have sample data that exhibits these problems, and can share it, I'd recommend that you send an e-mail containing copy of  the data to Blue Marble Geographics support (geohelp@bluemarblegeo.com).  That  way, the support team will see the problem and help you get to a solution as quickly as possible  

    Best regards,

    ~Jeff
  • sphillipssphillips Posts: 52
    Thanks for the help guys. The error was on my part as I hadn't realized that GM doesn't order scientific notation correctly with regards to ascending/descending values; which made me make an incorrect assumption about the values I was observing. My apologies for the error.
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