Hi, is anyone willing to check our i.vi code in https://trac.osgeo.org/grass/browser/grass/trunk/imagery/i.vi against https://bleutner.github.io/RStoolbox/rstbx-docu/spectralIndices.html (master: https://github.com/bleutner/RStoolbox) to see if there are any differences in the formulas? thanks Markus