packaging parameters for functions revisited

[Jon Norberg]

There have been several posts about this, so I tried to compile what I could find to compare speed and pretty coding:

http://nbviewer.ipython.org/urls/dl.dropboxusercontent.com/u/38371278/Function%20parms%20passing%20speed%20test.ipynb

Best speed is assigning values or variables inside the function

Second best is reassigning parameters from array for each parameter. The @pack/@unpack macro also is pretty fast and much prettier

Third best is separate parameters and global assignment (longer function call code if many parameters or/and just no no to use global?)

Slowest is using indexed array as parameters in function (but this is ugly to read) and immutable types

So I am wondering, did I miss any that improve speed/prettiness?

Best, Jon

[Mike Innes]

You don't seem to have tried keyword arguments – these are usually the best option if you have a large set of parameters to pass a single function. They may not fit your use case but they might be interesting to benchmark at least.

[Jon Norberg]

Do you mean using a dict to pack/unpack them?

function f(x; args...)

    ###

end

where args is a dict?

[Jon Norberg]

I added the keyword version (not sure it is as intended though....)

function with_keyword(x::Float64=1.1; a::Float64=1.0,b::Float64=2.0,c::Float64=3.0,d::Float64=4.0,e::Float64=5.0)

    dx= a*b*c*d*e::Float64

end

Results now are: (slower due to being on my macbook and couldn't change in the ijulia book yet):

@time for i in 1:N with_keyword(1.1) end

@time for i in 1:N Brute() end

@time for i in 1:N assignInF() end

@time for i in 1:N assignFromArray(f) end

@time for i in 1:N assignFromArray(ff) end

@time for i in 1:N packUnpack(p) end

@time for i in 1:N sepParams(a,b,c,d,e) end

@time for i in 1:N globadAssign() end

@time for i in 1:N indexedArray(f) end

@time for i in 1:N immutableType(s) end

@time for i in 1:N indexedArray(ff) end

elapsed time: 1.859415076 seconds (639983688 bytes allocated)
elapsed time: 1.824780742 seconds (639983688 bytes allocated)
elapsed time: 1.815331646 seconds (639983688 bytes allocated)
elapsed time: 2.260640645 seconds (640031792 bytes allocated)
elapsed time: 2.491979295 seconds (800031648 bytes allocated)
elapsed time: 2.498344644 seconds (800030640 bytes allocated)
elapsed time: 2.478566736 seconds (800001228 bytes allocated)
elapsed time: 2.605157314 seconds (799983688 bytes allocated)
elapsed time: 2.365273473 seconds (640021904 bytes allocated)
elapsed time: 2.58554929 seconds (800004984 bytes allocated)
elapsed time: 2.520120133 seconds (800021760 bytes allocated)

Thus, keyword goes close to top, but not sure how to pass a,b,c,d,e to the function using keywords

[cnbiz850]

Thanks very much for the summary.

It is very interesting that assignFromArray is much faster than
indexedArray. Can anyone explain why?