Return a copy of an R object with its class set to a given type of spectrum.
as.chroma_spct(x, ...)an R object
other arguments passed to "set" functions
A copy of x converted into a chroma_spct object.
Other constructors of spectral objects: as.calibration_spct,
as.cps_spct, as.filter_spct,
as.generic_spct,
as.object_spct, as.raw_spct,
as.reflector_spct,
as.response_spct,
as.source_spct, source_spct