Functions for rescaling respeciate data sets
rsp_rescale rescales the percentage weight records in
a supplied respeciate profile data set. This can be by profile or species
subsets, and rsp_rescale_profile and rsp_rescale_species provide
short-cuts to these options.
rsp_rescale(rsp, method = 2, by = "species")
rsp_rescale_profile(rsp, method = 1, by = "profile")
rsp_rescale_species(rsp, method = 2, by = "species")A respeciate object, a data.frame of respeciate
profiles.
numeric, the rescaling method to apply:
1 x/total(x);
2 x/mean(x);
3 x-min(x)/max(x)-min(x);
4 x-mean(x)/sd(x);
5 x/max(x).
The alternative 0 returns the records to their original
values.
character, when rescaling x with
rsp_rescale, the data type to group and rescale,
currently 'species' (default) or 'profile'.
rsp_rescale and rsp_rescale return the
respeciate profile with the percentage weight records rescaled using
the requested method. See Note.
Data sometimes needs to be normalised, e.g. when applying some
statistical analyses. Rather than modify source information in
SPECIATE and SPECIEUROPE, respeciate creates a
duplicate column .value which is modified by operations
like sp_rescale_profile and sp_rescale_species. This means
rescaling is always applied to the source information, rather than
rescaling an already rescaled value, and the EPA records are retained
unaffected. So, the original source information can be easily recovered.
Dowle M, Srinivasan A (2023). data.table: Extension of `data.frame`. R package version 1.14.8, https://CRAN.R-project.org/package=data.table.