[julia-users] Help Understanding an InexactError() in Code Sample

[zach]

I'm trying to understand why I'm getting an InexactError() in the following 
bit of code:

NTAB = 8

htab = [3280.84 * x for x in (0.0, 11.0, 20.0, 32.0, 47.0, 51.0, 71.0, 
84.852)]

ttab = [1.8 * x for x in (288.15, 216.65, 216.65, 228.65, 270.65, 270.65, 

                          214.65, 189.946)] 

ptab = [2116.21662 * x for x in  (1.0, 2.233611e-1, 5.403295e-2, 
8.5666784e-3, 

                                  1.0945601e-3, 6.6063531e-4, 3.9046834e-5, 
3.68501e-6)] 

gtab = fill(0.0, NTAB) 

for i = 1:NTAB-1 

    gtab[i] = ((ttab[i+1] - ttab[i]) / (htab[i+1] - htab[i]))

end 

gtab[NTAB] = 0.0
 
function atmosphere(alt::Float64) 

    h::Float64 = alt * REARTH / (alt + REARTH)      # convert geometric to 
                                                                            
                                    # geopotential altitude 
    i = 1
    j = NTAB 

    while true
        if h < htab[k]
            j = k
        else
            i = k
        end

        if j <= i+1

            break

        end

    end

end



At the line where I'm making the comparison with h < htab[k], I get an 
InexactError() when any value is passed into the function, but I'm not sure 
what the reason is as I'm still beginning with Julia.  If anyone would be 
kind enough to point out my mistake, then I would appreciate it.

Thanks!