Reclassify Tool

This tool was developed for those who would like to reclassify a grid theme and keep a record of the input classifications (minimum and maximum of the range of values for each output class). NOTE: The resolution of the output grid cannot be coarser than that of the input because the tool cannot record how Spatial Analyst handles a reduction in classes.

This function is based on the Reclassify function found in the Spatial Analyst's Analysis menu, but differs in three ways:

• if the input grid theme is integer, the user has the option of appending the reclassification information to the attribute table of that theme rather than creating a new grid
• the values that define each new classification are written to the output grid theme attribute table
• the dialog box used to define the reclassification is a "stripped-down" version of the Spatial Analyst tool

To Reclassify the values in a grid theme:

Make the grid theme you want to reclassify active.

Select 'Reclassify Tool...' from the SDM menu.

If the theme is an integer grid theme, there will be a pair of radio buttons on the dialog labelled 'Make new grid' and 'Append to attribute table'. Select one of these options. If neither is selected, the reclassification defaults to appending the reclassification information to the input grid theme attribute table.

To define a classification:

Click the 'Classify' button.

The dialog that is displayed works the same way as the classification dialog used with the ArcView legend editor and the Spatial Analyst reclassify tool.

The following steps are copied from ArcView On-Line Help.

1. Click the Classify button in ArcView's legend editor.
2. Choose a type of classification.
3. Set the number of classifications. You may use the drop-down method or click on the value box and directly type in your number of classes.
   If you chose the Standard Deviations classification, set the Interval that will determine the class breaks.
4. Choose the place at which your data values will be rounded.
5. Click OK.

For more information about defining a classification, refer to the ArcView On-line Help Topics:

legends, classification -> Set a classification
legends, classification, Classifying

To edit any of the 'Old Values' or the 'New Value' for an individual classification:

1. Double-click on the value(s) displayed in the Reclassify dialog. This will display an edit dialog.
2. Edit the values.
3. Click OK.

To apply the classification:

1. Click OK.
2. If a new grid is being generated, specify the name and location when prompted.