[julia-users] Dear @sprintf, you shouldn't do this

[J Luis]

It took me a while to figure out why it was erroring

Given this piece of a script

@show(sampr1, sampr2)
@show(typeof(sampr1), typeof(sampr2))
@show(@sprintf("-T%d/%d/1", sampr1[1], sampr2[1]))

it error ed with an incomprehensible error

sampr1 = [-1167.0]
sampr2 = [1169.0]
typeof(sampr1) = Array{Float64,2}
typeof(sampr2) = Array{Float64,2}
@sprintf("-T%d/%d/1",sampr1[1],sampr2[1]) = "-T-1167/1169/1"
ERROR: TypeError: non-boolean (Array{Bool,2}) used in boolean context
 [inlined code] from show.jl:127

it turned out that it wanted

@show(@sprintf("-T%d/%d/1", sampr1[1,1], sampr2[1,1]))

but the sampr1 & sampr2 are the result of a previous computation so not at 
all obvious of what was going on. Specially because accessing sampr1[1] is 
a perfectly valid statement

julia> sampr1 = zeros(1,1);
1x1 Array{Float64,2}:
 0.0

julia> sampr1[1]
0.0