RStoolbox icon indicating copy to clipboard operation
RStoolbox copied to clipboard

Spectral Mixture Analysis

Open ytarazona opened this issue 6 years ago • 1 comments

Thank you for the spectral unmixing function. However, I think the assignment of the name "mesma" seems to be wrong!. Since mesma means that multiple endmembers get the lowest RMSE. I executed the mesma function of RStoolbox for a total of 100 endmembers and the result is the number of fractions equal to the number of endmembers. Please I suggest to change the name of the function because "mesma" means to choose the endmember with the lowest RMSE from a set of endmembers. For more details see: Somers et al. 2011.

If I'm wrong, please let me know. Best regards,

ytarazona avatar Jan 05 '20 17:01 ytarazona

Yes, I'm confused about that as well. The example in the docs only shows a single endmember per class. I assumed that you could add more endmembers per class if you used the same name for each row, but that just makes the output have "name.1" as a class. It would be nice if you could clarify whether this is just regular SMA or alternatively add a bigger example that uses multiple endmembers per class.

GreatEmerald avatar Feb 18 '20 15:02 GreatEmerald

Thanks for flagging this. This has been addressed with the most recent update: For single endmember unmixing, each supplied endmember now represents a class to unmix (row by row). For multiple endmemeber unmixing, the column class can be used to group endmembers by class. If multiple endmembers per class are provided, mesma() will compute a number of SMA (determined through the new argument n_models) for multiple endmember combinations drawn from endmembers and will select the best fit per pixel based on the lowest RMSE.

See https://github.com/bleutner/RStoolbox/blob/master/NEWS.md#rstoolbox-041 for further info on the changes and ?RStoolbox::mesma after updating to the most recent github version.

16EAGLE avatar Apr 17 '24 16:04 16EAGLE