I don't think there is much to argue about, except perhaps names. 1. `linspace` returns a range, but is otherwise a drop-in replacement for an array, and should act as one for any naive user, other than sometimes being faster and taking less memory. This is not hidden from the user, yet they need not be concerned about it. It just works. (The array might be better in some cases, I suspect rarely.) 2. One might expect a `linspace` to show an array when typed into the REPL. With #13615 <https://www.google.com/url?q=https%3A%2F%2Fgithub.com%2FJuliaLang%2Fjulia%2Fpull%2F13615&sa=D&sntz=1&usg=AFQjCNESdEGtUlN_sTr8NTxWkldQaBZhYg>, post-0.4 the user will see that it is a range and also "what they expect." 3. It is true that `logspace` is an array and `linspace` is a range, and this is ugly. Perhaps there should be a `logrange` to go with `linrange`, or `logspace` should be modified to be a range. I do agree with these complaints. 4. The name `logspace` probably comes from Matlab, but otherwise has no significance and is not a great name. Perhaps it's worth keeping around for that reason; perhaps it should be stashed into a Matlab module. 5. As much as I was attracted here by the Matlab-alikeness, that can be a detriment. For example, Matlab overloads `diag` so you get two very different things for two different inputs. Whereas Mathematica has long, clear names, and `DiagonalMatrix` and `Diagonal` give a better clue what will happen. And as much as I love `eye`, `IdentityMatrix` is clearer. Other Matlab-isms: `tril`, `pcg`, `alim`, `shg`.
On Wednesday, October 21, 2015 at 3:16:58 PM UTC-4, Stefan Karpinski wrote: > > This thread is tragically long on opinions and short on arguments backing > them up. It occurs to me that we can write specialized methods for > collect(::LinSpace) that generate the collected version more efficiently > than generic iteration does, which eliminates one of the potential > arguments for just generating an array. > > On Wednesday, October 21, 2015, Gabriel Gellner <gabriel...@gmail.com > <javascript:>> wrote: > >> I agree with this downvote so much it hurts. The logspace/linspace is >> painfully ugly. linrange is the right name in my find for the iterator >> version. >> >> On Wednesday, 30 September 2015 10:31:55 UTC-7, Alex Ames wrote: >>> >>> Another downvote on linspace returning a range object. It seems odd for >>> linspace and logspace to return different types, and linrange provides the >>> low-memory option where needed. Numpy's `linspace` also returns an array >>> object. >>> I ran into errors when trying to plot a function over a linspace of x >>> values, since plotting libs currently expect vectors as arguments, not >>> range objects. Easily fixed if you know Julia well, but Matlab/Python >>> converts may be stymied. >>> >>> On Wednesday, September 30, 2015 at 12:19:22 PM UTC-5, J Luis wrote: >>>> >>>> I want to add my voice to the dislikers. Those are the type of >>>> surprises that are not welcome mainly for matlab users. >>>> >>>> quarta-feira, 30 de Setembro de 2015 às 16:53:57 UTC+1, Christoph >>>> Ortner escreveu: >>>>> >>>>> I also strongly dislike the `linspace` change; I like the idea though >>>>> of having `linspace` and `linrange`, where the former should give the >>>>> array. >>>>> Christoph >>>>> >>>>> >>>>> On Wednesday, 30 September 2015 10:21:36 UTC+1, Michele Zaffalon wrote: >>>>>> >>>>>> I just realize that the thread is about 0.3.11 and I am showing >>>>>> output for 0.4.0-rc2. Sorry for the noise. >>>>>> >>>>>> On Wed, Sep 30, 2015 at 11:17 AM, Michele Zaffalon < >>>>>> michele....@gmail.com> wrote: >>>>>> >>>>>>> >>>>>>> On Wed, Sep 30, 2015 at 9:50 AM, Milan Bouchet-Valat < >>>>>>> nali...@club.fr> wrote: >>>>>>> >>>>>>>> Le mercredi 30 septembre 2015 à 08:55 +0200, Michele Zaffalon a >>>>>>>> écrit : >>>>>>>> > Just curious: linspace returns a Range object, but logspace >>>>>>>> returns a >>>>>>>> > vector because there is no much use case for a LogRange object? >>>>>>>> > >>>>>>>> > @feza: I have also seen the deprecation warning going away after a >>>>>>>> > couple of calls, but I am not sure why. If you restart Julia, the >>>>>>>> > deprecations reappear. >>>>>>>> Deprecation warnings are only printed once for each call place. The >>>>>>>> idea is that once you're aware of it, there's no point in nagging >>>>>>>> you. >>>>>>>> >>>>>>>> Anyway, that warning is most probably not related to linspace at >>>>>>>> all, >>>>>>>> but rather to the array concatenation syntax resulting in an effect >>>>>>>> equivalent to collect(). If you show us a piece of code that prints >>>>>>>> the >>>>>>>> warning, we can give you more details. >>>>>>>> >>>>>>>> >>>>>>>> Regards >>>>>>>> >>>>>>> >>>>>>> Sorry, you are right, I was referring to the concatenation. >>>>>>> It prints it exaclty twice if I type it in the REPL, it always >>>>>>> prints it if I define it within a function e.g. a() = [1:3]. >>>>>>> >>>>>>> C:\Users\michele.zaffalon>julia >>>>>>> _ >>>>>>> _ _ _(_)_ | A fresh approach to technical computing >>>>>>> (_) | (_) (_) | Documentation: http://docs.julialang.org >>>>>>> _ _ _| |_ __ _ | Type "?help" for help. >>>>>>> | | | | | | |/ _` | | >>>>>>> | | |_| | | | (_| | | Version 0.4.0-rc2 (2015-09-18 17:51 UTC) >>>>>>> _/ |\__'_|_|_|\__'_| | Official http://julialang.org/ release >>>>>>> |__/ | x86_64-w64-mingw32 >>>>>>> >>>>>>> julia> [1:3] >>>>>>> WARNING: [a] concatenation is deprecated; use collect(a) instead >>>>>>> in depwarn at deprecated.jl:73 >>>>>>> in oldstyle_vcat_warning at abstractarray.jl:29 >>>>>>> in vect at abstractarray.jl:32 >>>>>>> while loading no file, in expression starting on line 0 >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> julia> [1:3] >>>>>>> WARNING: [a] concatenation is deprecated; use collect(a) instead >>>>>>> in depwarn at deprecated.jl:73 >>>>>>> in oldstyle_vcat_warning at abstractarray.jl:29 >>>>>>> in vect at abstractarray.jl:32 >>>>>>> while loading no file, in expression starting on line 0 >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> julia> [1:3] >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> julia> a() = [1:3] >>>>>>> a (generic function with 1 method) >>>>>>> >>>>>>> julia> a() >>>>>>> WARNING: [a] concatenation is deprecated; use collect(a) instead >>>>>>> in depwarn at deprecated.jl:73 >>>>>>> in oldstyle_vcat_warning at abstractarray.jl:29 >>>>>>> in a at none:1 >>>>>>> while loading no file, in expression starting on line 0 >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> julia> a() >>>>>>> WARNING: [a] concatenation is deprecated; use collect(a) instead >>>>>>> in depwarn at deprecated.jl:73 >>>>>>> in oldstyle_vcat_warning at abstractarray.jl:29 >>>>>>> in a at none:1 >>>>>>> while loading no file, in expression starting on line 0 >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> julia> a() >>>>>>> WARNING: [a] concatenation is deprecated; use collect(a) instead >>>>>>> in depwarn at deprecated.jl:73 >>>>>>> in oldstyle_vcat_warning at abstractarray.jl:29 >>>>>>> in a at none:1 >>>>>>> while loading no file, in expression starting on line 0 >>>>>>> 3-element Array{Int64,1}: >>>>>>> 1 >>>>>>> 2 >>>>>>> 3 >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> > On Wed, Sep 30, 2015 at 5:40 AM, feza <moham...@gmail.com> wrote: >>>>>>>> > > Strange it *was* giving me an error saying deprecated and that I >>>>>>>> > > should use collect, but now it's fine. >>>>>>>> > > >>>>>>>> > > >>>>>>>> > > On Tuesday, September 29, 2015 at 10:28:12 PM UTC-4, Sheehan >>>>>>>> Olver >>>>>>>> > > wrote: >>>>>>>> > > > fez, I'm pretty sure the code works fine without the collect: >>>>>>>> > > > when exp is called on linspace it converts it to a vector. >>>>>>>> > > > Though the returned t will be linspace object. >>>>>>>> > > > >>>>>>>> > > > On Wednesday, September 30, 2015 at 12:10:55 PM UTC+10, feza >>>>>>>> > > > wrote: >>>>>>>> > > > > Here's the code I was using where I needed to use collect >>>>>>>> (I've >>>>>>>> > > > > been playing around with Julia, so any suggestions on this >>>>>>>> code >>>>>>>> > > > > for perf is welcome ;) ) . In general linspace (or the : >>>>>>>> > > > > notation) is also used commonly to lay a grid in space for >>>>>>>> > > > > solving a PDE for some other use cases. >>>>>>>> > > > > >>>>>>>> > > > > function gp(n) >>>>>>>> > > > > n = convert(Int,n) >>>>>>>> > > > > t0 = 0 >>>>>>>> > > > > tf = 5 >>>>>>>> > > > > t = collect( linspace(t0, tf, n+1) ) >>>>>>>> > > > > sigma = exp( -(t - t[1]) ) >>>>>>>> > > > > >>>>>>>> > > > > c = [sigma; sigma[(end-1):-1:2]] >>>>>>>> > > > > lambda = fft(c) >>>>>>>> > > > > eta = sqrt(lambda./(2*n)) >>>>>>>> > > > > >>>>>>>> > > > > Z = randn(2*n) + im*randn(2*n) >>>>>>>> > > > > x = real( fft( Z.*eta ) ) >>>>>>>> > > > > return (x, t) >>>>>>>> > > > > end >>>>>>>> > > > > >>>>>>>> > > > > >>>>>>>> > > > > On Tuesday, September 29, 2015 at 8:59:52 PM UTC-4, Stefan >>>>>>>> > > > > Karpinski wrote: >>>>>>>> > > > > > I'm curious why you need a vector rather than an object. >>>>>>>> Do >>>>>>>> > > > > > you mutate it after creating it? Having linspace return an >>>>>>>> > > > > > object instead of a vector was a bit of a unclear >>>>>>>> judgement >>>>>>>> > > > > > call so getting feedback would be good. >>>>>>>> > > > > > >>>>>>>> > > > > > On Tuesday, September 29, 2015, Patrick Kofod Mogensen < >>>>>>>> > > > > > patrick....@gmail.com> wrote: >>>>>>>> > > > > > > No: >>>>>>>> > > > > > > >>>>>>>> > > > > > > julia> logspace(0,3,5) >>>>>>>> > > > > > > 5-element Array{Float64,1}: >>>>>>>> > > > > > > 1.0 >>>>>>>> > > > > > > 5.62341 >>>>>>>> > > > > > > 31.6228 >>>>>>>> > > > > > > 177.828 >>>>>>>> > > > > > > 1000.0 >>>>>>>> > > > > > > >>>>>>>> > > > > > > On Tuesday, September 29, 2015 at 8:50:47 PM UTC-4, Luke >>>>>>>> > > > > > > Stagner wrote: >>>>>>>> > > > > > > > Thats interesting. Does logspace also return a range? >>>>>>>> > > > > > > > >>>>>>>> > > > > > > > On Tuesday, September 29, 2015 at 5:43:28 PM UTC-7, >>>>>>>> Chris >>>>>>>> > > > > > > > wrote: >>>>>>>> > > > > > > > > In 0.4 the linspace function returns a range object, >>>>>>>> > > > > > > > > and you need to use collect() to expand it. I'm also >>>>>>>> > > > > > > > > interested in nicer syntax. >>>>>>>> >>>>>>> >>>>>>> >>>>>>
