I have an undetermined stable isotope (SI) trophic model with 2 tracers and 5 sources for a consumer (mix). To address this undetermined model I applied the mixSIR.unknownGroupsR function (http://conserver.iugo-cafe.org/user/eric.ward/Mixing%20model%20with%20unknown%20groups) to combine sources into groups and estimate the proportional contributions of the resultant grouped sources to the consumer (Ward EJ, Semmens BX, Phillips DL, et al (2011) Ecosphere 2:art19. doi: 10.1890/ES10-00190.1). Among the input data required by the R function are: a matrix with the consumer SI data (X); a matrix of raw source SI means (u); a matrix of raw SI source variances (v); and a matrix of sample sizes (k). However, the unknownGroups.R. function does not require the input of a matrix of means (and variances) isotope fractionation values (i.e. trophic fractionation or discrimination) for each of the sources used in the model, as usual in other mixing models (e.g.: mixSIR, SIAR, MixSIAR, FRUITS).
hi Pablo
we will need to check with Brian Stock for this who maintains the package. Could you post your question as an issue on github instead please as that is where questions are collated. https://github.com/brianstock/MixSIAR/issues
cheers
andrew
Pablo,
I got a problem in runing mixSIR.unknownGroupsR function in my data. How do you decide inputThresh in mixSIR.unknownGroupsR function? I have 7 tracers and 9 groups.
Kind regards,
Hari
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