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GispoCoding / eis_toolkit

Python library for mineral prospectivity mapping
https://eis-he.eu/
European Union Public License 1.2
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Add functions for CoDA #218

Closed em-t closed 9 months ago

em-t commented 11 months ago

Add functions necessary to perform analysis on compositional data:

The following transformations were requested:

  1. pairwise logratio transform
  2. additive logratio transform (alr)
  3. center logratio transform (clr)
  4. isometric logratio transform (ilr)
  5. pivot coordinates
em-t commented 11 months ago

Upon initial search, the python package pyrolite seems to contain many of these. It includes a submodule for handling compositional data, which has an implementation for ALR, CLR, and ILR transforms and their inverses. (License information here, and relevant source code here.)

The python package compositional also contains some of these.

"Pivot coordinates" probably refers to similar functionality as in pivotCoord, included in the R package robCompositions for CoDA. It also contains the method pwlr for performing pairwise logratio transforms.

The R package coda.base (which is partially implemented in c++ for better performance) also contains all the transform functions listed.

nmaarnio commented 9 months ago

Implemented and merged in PR #244