Overlap statistics measure boundary spatial association. You can evaluate whether the association is statistically unusual through comparison with Monte Carlo randomizations of the boundary locations. Overlap results consist of histograms for each statistic and a summary table.
Boundary overlap analysis creates a set of histograms and a table of boundary overlap statistics. You can choose not to view the histograms when you perform the analysis (clear the "show histograms after overlap" box). If you accept the default output, you will see a histogram for OG, OH, OGH and OS. The histograms show the values for these statistics from Monte Carlo randomizations of the boundaries. The observed overlap values are shown as a red bar on the histogram. Viewing the histograms allows you to visually assess how unusual the observed values are compared to the randomizations.
The table displays the observed value for each of the four statistics, the Z-score for the observed value, the mean and standard deviation of the distribution and the upper and lower p-values. Below the statistics is a list of the values in each of the randomizations.
If you chose to standardize the output, BoundarySeer will display the Z-score for each statistic in each randomization. The Z-score standardizes by dividing by the standard deviation. For those statistics that have no variance, the standard deviation is zero and the Z-score cannot be calculated. In this instance, BoundarySeer will display "DIV/0" in the table and the histogram of that statistic will not be produced.
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