GPU Array fun inside for loop - slower execution

I have a function that I know executes correctly on the GPU using arrayfun. I also know that the execution is very quick ~0.1 seconds. I essentially itterate over the function with slightly different inputs lets say 100 times. What does make sense is that if i were to copy and past the command line and execute it as 100 lines of code instead of a for loop it is much slower

for i = 1:100

out = arrayfun(@fun(a),gpuArray)

end

can anyone explain what i am seeing?

[Walter Roberson]

@fun(a) is not valid syntax

You have to be careful with gpu timing. gputimeit is recommended.

[Joss Knight]

I think you're going to have to post your actual code because it's hard to work out exactly what you mean. If your function is an anonymous function, for instance, then it's easy to explain the difference.