Introduction
Spatial Data Modeller, SDM, is a collection of tools for adding categorical maps with
interval, ordinal, or ratio scale maps to produce a predictive map of where something of
interest is likely to occur. This release of SDM has been modified to only work with
ArcGIS 9.3. The SDM modifications in this version have to do with changes in Band
Collection Statistics and intersection of points in rasters. These errors caused by
changes in Band Collection Statistics and intersection of points in rasters can be
subtle; tools such as Calculate Weights, Area Frequency, NN Input Files, MS Large
and MS Small compute had to be modified. All of the tools have help files that include
references to publications discussing the applications of the methods implemented in the
tool. Several of the tools create output rasters, tables, or files that require the user to enter
a name. Default values are provided in most cases to serve as suggestions of the style of
naming that has been found useful. These names, following ArcGIS conventions, can be
changed to meet the user’s needs. To make all of the features of SDM work properly it is
required that several Environment parameters are set. See the discussion of Environment
Settings below for the details. The Weights of Evidence, WofE, and Logistic Regression,
LR, tools addresses area as the count of unit cells. It is assumed in the WofE and LR tools
that the data has spatial units of meters. If your data has other spatial units, these WofE
and LR tools may not work properly.
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