[julia-users] array element assignment very expensive in profile

[cnbiz850]

Profile shows the two lines in the function being very expensive. Is 
there anything inappropriate?  Any way to improve?

function NoUpdate(data::Data)
    data.cum[data.i] = data.cum[data.i-1]
    data.i += 1
end
type Data
    cum::Array{Float32,1}
    i::Int32
    ...
end