000915: The General G statistic was designed to work with positive attribute values.

Description

The mathematics associated with this tool can only evaluate spatial clustering of high and low positive values. It cannot be used to assess clustering for fields containing negative values.

Solution

Use a different input field for this analysis. Select a field that only contains values greater than or equal to 0. Alternatively, adjust the values in the field (add a constant) so that all values are greater than 0.