GSMNP:Notebook/Maxent/Creating a Range Map

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Current revision (22:41, 6 August 2014) (view source)
 
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**hab_species abbrev = pred_species abbrev > threshold
**hab_species abbrev = pred_species abbrev > threshold
**OK
**OK
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After following the above recipe, the resulting grid will be in Arc binary grid format and have a value of 1 for habitat pixels, 0 for non-habitat pixels, and NODATA for pixels not inside the analysis mask [[File:figure3.png|frame|alt=Binary Range Map|Figure 3, Binary Range Map]]
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After following the above recipe, the resulting grid will be in Arc binary grid format and have a value of 1 for habitat pixels, 0 for non-habitat pixels, and NODATA for pixels not inside the analysis mask [[Image:Gsm-maxent-fig3.jpg|thumb|alt=Binary Range Map|Figure 3, Binary Range Map]]

Current revision

A desirable model output not included in the standard html output is a binary range map for the species. This map has only 2 categories, habitat and non-habitat. The delineation of habitat must be chosen by the user based on the binomial test results in the Analysis of omission and commission section (5.1). As an example, we chose a Balanced training omission, predicted area and threshold value threshold for the Hooded Warbler model. The logistic threshold was 0.139. Our task is to create a binary map from the original logistic projection map where values greater than 0.139 are true (1) and values less than 0.139 are false (0). The procedure follows:

  • Import the output logistic ASCII grid into ArcMap.

ArcToolbox\RightarrowConversion Tools\RightarrowTo Raster\RightarrowASCII to Raster

    • Input ASCII raster file: path to output folder/species name_ASCII.asc – Output raster: path to output folder/pred_species abbrev
    • Output data type (optional): FLOAT
    • Set Spatial Analyst Workspace to output folder Spatial Analyst\RightarrowOptions...\RightarrowGeneral
    • Working Directory: path to output folder
  • Compute the logical comparisons
  • Spatial Analyst\RightarrowRaster Calculator
    • hab_species abbrev = pred_species abbrev > threshold
    • OK
After following the above recipe, the resulting grid will be in Arc binary grid format and have a value of 1 for habitat pixels, 0 for non-habitat pixels, and NODATA for pixels not inside the analysis mask
Figure 3, Binary Range Map
Figure 3, Binary Range Map
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