It doesn't directly answer your question, but one thought is to not force many of these ranges to become vectors. For instance, the line t = t0 + [0:Ns-1;]*Ts;
could also have been written t = t0 + (0:Ns-1)*Ts; and that would still be valid input to functions like sin, cos, exp, etc... On Wednesday, October 21, 2015 at 3:11:44 AM UTC-4, Gabriel Gellner wrote: > > I find the way that you need to use `linspace` and `range` objects a bit > jarring for when you want to write vectorized code, or when I want to pass > an array to a function that requires an Array. I get how nice the iterators > are when writing loops and that you can use `collect(iter)` to get a array > (and that it is possible to write polymorphic code that takes LinSpace > types and uses them like Arrays … but this hurts my small brain). But I > find I that I often want to write code that uses an actual array and having > to use `collect` all the time seems like a serious wart for an otherwise > stunning language for science. ( > https://github.com/JuliaLang/julia/issues/9637 gives the evolution I > think of making these iterators) > > > > For example recently the following code was posted/refined on this mailing > list: > > > > function Jakes_Flat( fd, Ts, Ns, t0 = 0, E0 = 1, phi_N = 0 ) > > # Inputs: > > # > > # Outputs: > > N0 = 8; # As suggested by Jakes > > N = 4*N0+2; # An accurate approximation > > wd = 2*pi*fd; # Maximum Doppler frequency > > t = t0 + [0:Ns-1;]*Ts; > > tf = t[end] + Ts; > > coswt = [ sqrt(2)*cos(wd*t'); 2*cos(wd*cos(2*pi/N*[1:N0;])*t') ] > > temp = zeros(1,N0+1) > > temp[1,2:end] = pi/(N0+1)*[1:N0;]' > > temp[1,1] = phi_N > > h = E0/sqrt(2*N0+1)*exp(im*temp ) * coswt > > return h, tf; > > end > > > > From <https://groups.google.com/forum/#!topic/julia-users/_lIVpV0e_WI> > > > > Notice all the horrible [<blah>;] notations to make these arrays … and it > seems like the devs want to get rid of this notation as well (which they > should it is way too subtle in my opinion). So imagine the above code with > `collect` statements. Is this the way people work? I find the `collect` > statements in mathematical expressions to really break me out of the > abstraction (that I am just writing math). > > > > I get that this could be written as an explicit loop, and this would > likely make it faster as well (man I love looping in Julia). That being > said in this case I don't find the vectorized version a performance issue, > rather I prefer how this reads as it feels closer to the math to me. > > > > So my question: what is the Juilan way of making explicit arrays using > either `range (:)` or `linspace`? Is it to pollute everything with > `collect`? Would it be worth having versions of linspace that return an > actual array? (something like alinspace or whatnot) > > > Thanks for any tips, comments etc >
