Feature request #12030

Ln (natural logarithm) button in Raster Calculator

Added by Mark Cresswell almost 6 years ago. Updated over 5 years ago.

Status:Closed
Priority:Normal
Assignee:-
Category:Raster Calculator
Pull Request or Patch supplied:No Resolution:fixed/implemented
Easy fix?:No Copied to github as #:20233

Description

It would be great if an 'Ln' logarithm function was available in the Raster Calculator. This would allow temperature and other geophysical parameters to be calculated from thermal radiance bands. The plugin 'RasterCalc' solved this for older versions of QGIS, but is not compatible with the current release.

History

#1 Updated by George Rodrigues da Cunha Silva over 5 years ago

This is true. I'm developing a plugin that obviously depends on such calculation.

For what I can see in the repository, it seems simple to implement, but I do not have c++ skills or the environment to properly rig everything and do all the testing.

These are the supported nodes:

https://github.com/qgis/QGIS/blob/release-2_8/src/analysis/raster/qgsrastercalcnode.h#L38

We should support log and logn.

This is where the magic happens:

https://github.com/qgis/QGIS/blob/release-2_8/src/analysis/raster/qgsrastermatrix.cpp

#2 Updated by Jürgen Fischer over 5 years ago

  • Resolution set to fixed/implemented
  • Target version deleted (Future Release - High Priority)
  • Status changed from Open to Closed

implemented in 7019db88

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