How to import an Arcgis raster to Idrisi considering the “NoData” values

19 Nov

Hi again! The conversion between Arcgis rasters such as grids and others to the Idrisi format is fairly simple. However, when you run some of the analyses in Idrisi such as Varcost or to use the Land Change Modeller, you will realize soon that Idrisi gives you an error such as “floating point overflow” and others. This seems to occur when one or more of the rasters you are using have NoData values that are extremely large such as -9999.

The way to solve it is to reclassify your raster either in Arcgis or Idrisi:

1. In arcgis with the reclassification tool delete all the entries leaving only the “NoData” value. Give these values a new value of -1 (for instance)

2. If you have your file already in Idrisi, run reclassify and if you have for instance values of -9999 where in arcgis was NoData, you just Assign a new value of -1 To all values from -9999 To just less than 0.

I hope this is useful for somebody because it took me a while to find the solution to this 🙂

Have a great day!

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One Response to “How to import an Arcgis raster to Idrisi considering the “NoData” values”

  1. huraira August 13, 2013 at 8:34 am #

    hi, please i have a landsat TM image with 3 bands only(visible in ArcINFO). I have been trying to import it into idrisi by converting it but its giving me this error code saying unavailable disk space. i tried reclassifying it as u said, but the result is not successful i.e. giving me a polygon diagram. please what should i do?

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