reclassify tool - classes of inequal size

NinaEichler

Hello,

I am taking a GIS course and have the following problem:

I do have a slope layer and I am supposed to classify the slope in 3 classes of unequal size using the reclassify tool. I got following instructions:

Select Tuapaka_slope as the Input Raster
• Click on Classify
• Change the Classes to 3
• Then change the break values to 10, 30 and leave the last value as is
• Name the Output layer

click on run

( I am using ArcGis Pro)

I realize I could easily do it using the symbology tool by using unique classes and manually change it there but I am instructed to use the reclassify (spatial analyst tool). However, when I (click on classify and change classes to 3 it changes the classes to 3 classes of equal size, when I then change the values in the table and click on "run" it automatically changes the classes back to 9? So how can I create 3 classes of unequal size using the reclassify tool ??? It would be great if someone could help.

Anonymous User

Hi Nina,

When you said " when I (click on classify and change classes to 3 it changes the classes to 3 classes of equal size, when I then change the values in the table and click on "run" it automatically changes the classes back to 9", it sounds like a bug to me. However, I cannot reproduce it in ArcGIS Pro 2.5, may I know which version of the software are you using?

Another thing you can try is to set the symbology of your slope layer first. You can first set Equal Interval method in Symbology pane and select number of classes as 3. Then manually edit the Upper value column with the break values you want.

Now if you go back and open Reclassify tool, and select your slope layer as the input raster, the Reclassification table parameter will get the class break you set in the Symbology. So you don't need to manually type in any values.

Hope it helps.