Subset planning units from a RapData(),
RapUnsolved(), or RapSolved() object.
pu.subset(x, pu)
# S3 method for RapData
pu.subset(x, pu)
# S3 method for RapUnsolOrSol
pu.subset(x, pu)RapData(), RapUnsolved(), or
RapSolved() object.
integer vector to specify the index of planning units to
subset.
RapData() or RapUnsolved() object depending
on input object.