Raster calculator - problems with syntax

Question

I have a raster layer with values ranging from 0.00597303 to 0.102894 and I want to assign specific number representing a group to specific range of values:

Group 4: x >= 0.1
Group 3: 0.01 <= x < 0.1
Group 2: x < 0.01

I am using the following syntax:

("Ri_Q50@1" >= 0.1) * 4 + (("Ri_Q50@1" >= 0.01) AND ("Ri_Q50@1" < 0.1)) * 3 + ("Ri_Q50@1" < 0.01) * 2

However, the output file only has assigned group 2 and 3 but not the 4th group (x >= 0.1). What could be the reason?

Note: When I use the Raster pixels to points and check the output point layer there is 12 points having exceeded the condition for 4th group - ie 12 pixels has value above 0.1).

Answer 1

An alternative to Raster Calculator, you can use Reclassify by table tool from Processing toolbox -> Raster Analysis -> Reclassify by table. Then use the range of values that you want to reclassify to integer values as you can see in the example below:

Make sure to select the correct Range boundaries from the tool above. This example uses min < value <= max. You may need to change it based on your desired analysis.