Bug report #20479
Natural breaks (Jenks) classes not computed correctly from expression
| Status: | Open | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | Symbology | ||
| Affected QGIS version: | 3.4.1 | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 28299 |
Description
QGIS doesn't compute the classes using Natural Breaks (Jenks) correctly. The first class only has one value and the subsequent classes are wrong.
Here are the classes as they should be computed: 
Here are the classes that QGIS computes:
Note that the first class is value - same value. Also affects v3.2.3.
History
#1
Updated by Giovanni Manghi about 6 years ago
- Status changed from Open to Feedback
- Category changed from Unknown to Symbology
Can you attach a sample of the data?
#2
Updated by Joshua Biagio about 6 years ago
- File totalreg.shp.zip added
Giovanni Manghi wrote:
Can you attach a sample of the data?
Here is a shapefile that contains the sample data. You'll need to set the column as an expression: "Reg_Total" / "POP2000".
#3
Updated by Giovanni Manghi about 6 years ago
- Operating System deleted (
Windows 10 64-bit) - Status changed from Feedback to Open