SpecificS failure

[tkoenig1]

Also carried over from a coment of #24. The NaNs and the vales around 2.5 are wrong.

julia> p=range(43,47,step=0.2)
43.0:0.2:47.0

julia> SpecificS.(p,625.)
21-element Vector{Float64}:
   3.5895054305809357
   3.5885691485074847
   3.587637073227272
   3.5867091589138083
   3.5857853605445835
   3.5848656338758413
   3.583949935427027
   3.583038222462932
   2.519046247951557
 NaN
 NaN
 NaN
 NaN
   2.520978997154807
   2.5213657730882586
   2.5217526246909796
   2.5221395520967236
   2.5225265554362766
   2.522913634845939
   2.5233007904580256
   2.5236880224049116

julia> 

[longemen3000]

sorry, i haven't look at this yet, but i know where the problem lies. again, it is a initialization of the density in the region 3.