Help data is hand-written; if no one has documented a function yet, then it just tells you how many methods there are. `methods(sumabs2)` would show you the method signatures.
If you want to add to the help documentation, you can edit this file: https://github.com/JuliaLang/julia/blob/master/doc/helpdb.jl (You can either use the github interface to edit it online, or, if you have the Julia source, edit the file locally and make a pull request.) -- Leah On Wed, Jul 16, 2014 at 10:36 AM, Neal Becker <[email protected]> wrote: > Dahua Lin wrote: > > > With the latest Julia, you can do this by > > sumabs2(x) > > > > Dahua > > > > > > On Wednesday, July 16, 2014 9:57:54 AM UTC-5, Neal Becker wrote: > >> > >> As a first exercise, I wanted to code magnitude squared of a complex > >> 1-d array. Here is what I did: > >> > >> mag_sqr{T} (x::Array{Complex{T},1}) = > >> sum(real(x).*real(x)+imag(x).*imag(x)) > >> > >> Is this a "good" approach? I'm wondering if it's not very efficient, > >> since I > >> expect it would compute matrixes of element-wise products first, rather > >> than > >> doing the sum as a running summation (like a loop in c++). > >> > >> Can you suggest something "better"? > >> > >> > > Not exactly answering my question, as I was looking for a learning > opportunity. > But this raises another question: > > In [2]: > > help(sumabs2) > INFO: Loading help data... > sumabs2 (generic function with 2 methods) > > Why is the help data not being shown? (this is ipython notebook interface) > >
