pix_to_world() when naxis=3

[andferrari]

When naxis=3, the third pixel coordinate in pix_to_world() must be a Float

julia> wcs = WCSTransform(3; cdelt = [-0.066667, 0.066667, 1e4],
                                 ctype = ["RA---AIR", "DEC--AIR", "FREQ"], crpix = [-234.75, 8.3393, 1.0],
                                 crval = [0., -90, 1e8], pv    = [(2, 1, 45.0)])
WCSTransform(naxis=3)

julia> pix_to_world(wcs, [0, 0, 0.0])
3-element Array{Float64,1}:
 267.96547027027646
 -73.73660748999083
   9.999e7

julia> pix_to_world(wcs, [0, 0, 0])
ERROR: MethodError: no method matching pix_to_world(::WCSTransform, ::Array{Int64,1})

[sefffal]

I believe the issue is actually that pix_to_world and world_to_pix both require an array of floats. The first example works because the array is automatically promoted to be all floats.