decomposition does not work properly with hyperSpec objects containing no spectra

[galaxismad]

Using the decomposition function with an hyperSpec function containing no spectra leads to an error with out of bounds description.

Error in xj[i, , drop = FALSE] : Indexing out of bounds

related issue: #288

[GegznaV]

@galaxismad could you provide a minimal reproducible example to test this behavior?

[galaxismad]

spc <- new("hyperSpec", wavelength = 1:20, spc = matrix(NA, ncol = 20, nrow = 0))
decomposition(spc, matrix(20:1, ncol = 20, nrow = 1), scores = FALSE)

It would be expected, that the matrix is replacing the empty spc column, as a valid wavelength axis is available.

[GegznaV]

@galaxismad thank you for the clarification.

[GegznaV]

Possibly related: #144