Steven G. Johnson wrote:
>
>
>
> On Monday, September 12, 2016 at 7:59:33 AM UTC-4, DNF wrote:
>>
>> function(p::pnseq)(n,T=Int64)
>>
>>>
> Note that the real problem with this function declaration is that the type
> T is known only at runtime, not at compile-time. It would be better to
> do
>
> function (p::pnseq){T}(n, ::Type{T}=Int64)
Thanks! This change made a big difference. Now PnSeq is only using a small
amount of time, as I expected it should. I prefer this syntax to the
alternative you suggest below as it seems more logical to me.
>
> since making the type a parameter like this exposes it as a compile-time
> constant. Although it would be even more natural to not have to pass the
> type explicitly at all, but rather to get it from the type of n, e.g.
>
>
> function (p::pnseq){T<:Integer}(n::T)
>
> I have no idea whether this particular thing is performance-critical,
> however. I also see lots and lots of functions that allocate arrays, as
> opposed to scalar functions that are composed and called on a single
> array, which makes me think that you are thinking in terms of numpy-style
> vectorized code, which doesn't take full advantage of Julia.
>
> It would be much easier to give pereformance tips if you could boil it
> down to a single self-contained function that you want to make faster,
> rather than requiring us to read through four or five different submodules
> and
> lots of little one-line functions and types. (There's nothing wrong with
> having lots of functions and types in Julia, it is just that this forces
> us to comprehend a lot more code in order to make useful suggestions.)
Nyquist and CoefFromFunc are normally only used at startup, so they are
unimportant to optimize.
The real work is PnSeq, Constellation, and the FIRFilters (which I didn't
write - they are in DSP.jl). I agree that the style is to operate on and
return a large vector.
I guess what you're suggesting is that PnSeq should return a single scalar,
Constellation should map scalar->scalar. But FIRFilter I think needs to be
a vector->vector, so I will take advantage of simd?
