Spatial cold hot spot analysis
Definition and principle
Hotspot analysis tools can calculate Getis-Ord Gi * statistics (called Gi-asterisks) for each element in the data set. With the obtained z-score and p-value , you can know the spatial clustering of high-value or low-value features. The way this tool works is: View every feature in the environment of nearby features. High-value elements tend to attract attention, but may not be a hot spot with statistical significance. To become a hot spot with significant statistical significance, the elements should have high values and be surrounded by other elements that also have high values. The partial sum of an element and its neighbors will be compared with the sum of all elements; when the partial sum is so different from the expected partial sum that it cannot be a randomly generated result, a statistically significant Learning the z-score . If FDR correction is applied , the statistical significance is adjusted according to multiple tests and spatial dependence.
Hot spot analysis is based on the idea of zero hypothesis testing commonly used in statistical inference. Because our eyes and brain are all patterns behind analyzing data all the time, even randomly distributed events may show a certain degree of agglomeration in space. The goal of hotspot analysis tools is to identify areas with statistically significant clustering. Because this shows that these events are being affected by certain spatial process factors, there is a spatial correlation.
Definition from argis official website
Let's look at the actual operation
The data preparation and the normal spatial distribution are consistent, such as
Ordinary spatial distribution map-you can see where is high and where is low. But if you want quantitative analysis, then you need to use hot spot analysis tools
First, let's see if he is random globally, accumulated or discrete
因此First carry out spatial autocorrelation analysis
The options are as follows
Results: with spatial clustering characteristics
Therefore, space cold spot analysis can be performed
Options
The result is the following figure
After typography and font adjustment
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