Hands-On Geospatial Analysis with R and QGIS

Reclassifying rasters

Sometimes, for research purposes, it might be necessary to group numeric values into some categories. For elevation data, we can group the values into some meaningful classes. For example, we can classify elevation data into various categories using processing. Now, we'll reclassify the dem_chittagong.tiff elevation data into four classes. The detailed instructions for doing so are as follows:

1. We load dem_chittagong.tiff first.
2. If we want to recode values from the lowest to 10 as 1, from 10 to 100 as 2, from 100 to 500 as 3, and from 500 upward as 4, we would need to write down the following in a text file:

3. Save it ...