Re: [julia-users] Re: Error messages related to macros

2015-04-06 Thread Mauro
I don't know whether that is mentioned in those issues but one trick is to have a function fabricating the expression and call that in the macro: mymacro_fn(args...) = ... macro mymacro(args...) mymacro_fn(args...) end If something goes wrong debug it with calling the function directly which

[julia-users] Re: Julia on Vagrant

2015-04-06 Thread Patrick O'Leary
This hasn't been updated in a while, so it's probably just broken (I don't think it sees much use). `jlmake` is just an alias, defined in /home/vagrant/.bash_aliases during provisioning, which sets as many of the USE_SYSTEM_dep variables to true as it can. Dependencies have probably gotten

[julia-users] Re: Performance of random access sparse matrix algorithm

2015-04-06 Thread Tony Kelman
Ah, that explains it. I'm not sure if there's a way to disable or warn on non-const globals, but it's a good question. @code_warntype did a pretty good job at pinpointing the problems they caused, and Lint.jl also might have caught them (would need to try it). On Monday, April 6, 2015 at

Re: [julia-users] Exporter for compressed binary unstructured grid VTK XML files.

2015-04-06 Thread Kristoffer Carlsson
Hello Rob, Thank you for your comments and sorry for my late answer. I have been away for a while. I should have stressed in my post that the files I attached was only a minimum working example from which someone should easily be able to write their own custom exporter. The data structures in

[julia-users] Re: Performance of random access sparse matrix algorithm

2015-04-06 Thread David Gleich
Thanks so much for the help. Lint.jl does catch the use of global. Well, it says it's undefined because it hasn't been defined yet... I guess this is a good reason to put methods first. Let me see how this does after a few more complex modifications! David On Monday, April 6, 2015 at

Re: [julia-users] Extreme garbage collection time

2015-04-06 Thread Adam Labadorf
Thanks for the replies. I took your suggestions (and reread the scope section of the docs) and am still experiencing the gc creep. Below is the complete program, with the notable changes that I wrapped the main computation in a function and eliminated all references to global variables inside.

[julia-users] Code optimization

2015-04-06 Thread Dash Khash
Hi, Intrigued by https://github.com/jesusfv/Comparison-Programming-Languages-Economics, I did a little exercise function valuefnc(x, V) n=length(x) a=0.1; b=0.9; out=zeros(n); for(i=1:n) out[i]=maximum(log((1 + x[i]^a) .- x) .+ b*V[i]); end out end And for the grid

[julia-users] Re: Code optimization

2015-04-06 Thread Viral Shah
There is a lot of memory that gets allocated in the maximum(...) line. Ideally, our memory management would be able to do something better than allocating memory for every loop iteration - but that is already happening. In the meanwhile, I can devectorize and get this: function valuefnc(x, V)

[julia-users] Re: Code optimization

2015-04-06 Thread Dash Khash
Thank you very much for prompt reply, Viral. I see now that de-vectorization is crucial for performance in Julia( which actually is my cognitive sticking point). I've also tried RcppArmadillo,only to find out that it runs only slightly faster (around 1sec). As you said, logs and pows take most

Re: [julia-users] Code optimization

2015-04-06 Thread Viral Shah
That’s right - if you are doing lots of vectorized operations - effectively time is spent in C code, and all languages tend to perform equally. Often devectorizing gives much larger speedups - but in this case, the running time is dominated by the math functions. -viral On 06-Apr-2015, at

[julia-users] Re: derivatives of Chebyshev polynomials

2015-04-06 Thread Alan Edelman
there could be so many ways to do this that it might be worth asking about the use case the derivatives, of course, satisfy the same three term recurrence but with different initial conditions so it might be worth knowing if 0. whether this is worth optimizing a great deal or just a little

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Andreas Noack
Which pca? 2015-04-06 6:53 GMT-07:00 Steven Sagaert steven.saga...@gmail.com: does pca() center the input output data or do you have to do that yourself?

[julia-users] does pca() center the data?

2015-04-06 Thread Steven Sagaert
does pca() center the input output data or do you have to do that yourself?

Re: [julia-users] updating an array

2015-04-06 Thread Stefan Karpinski
Not sure it's trivial as this but endif is not a keyword in Julia. On Apr 6, 2015, at 9:05 AM, Jim Christoff j.christof...@gmail.com wrote: First, Julia is a great replacement for Octave and in most cases C. I have used Octave for decades and Julia for a year or so. I still have problems

[julia-users] updating an array

2015-04-06 Thread Jim Christoff
First, Julia is a great replacement for Octave and in most cases C. I have used Octave for decades and Julia for a year or so. I still have problems making the conversions. Any assistance will be greatly appreciated. This is short example of the modified Octave code that I have tried to

[julia-users] Re: derivatives of Chebyshev polynomials

2015-04-06 Thread Paulo Jabardo
There is a recurrence relation for the derivatives but it involves the Chebyshev polynomials of second kind. Chebyshev polynomials of first kind: T_0(x) = 1 T_1(x) = x T_(n+1)(x) = 2x.T_n(x) - T_(n-1)(x) Chebyshev polynomials of second kind: U_0(x) = 1 U_1(x) = 2x U_(n+1)(x) = 2x.U_n(x) -

Re: [julia-users] Re: [ANN] JuliaIO and FileIO

2015-04-06 Thread Tim Holy
I haven't yet had time to look at FileIO, but if the code has been lifted from Images, then it uses the magic bytes in preference to the file extension (when the magic bytes are recognized). Best, --Tim On Monday, April 06, 2015 06:30:40 AM Sebastian Good wrote: Very interesting project. I've

Re: [julia-users] Re: derivatives of Chebyshev polynomials

2015-04-06 Thread Alan Edelman
If all you wanted was one derivative, i'd consider just an arccos and sines formula i gathered it was multiple derivatives desired On Mon, Apr 6, 2015 at 8:04 AM, Paulo Jabardo pjaba...@gmail.com wrote: There is a recurrence relation for the derivatives but it involves the Chebyshev

Re: [julia-users] Re: derivatives of Chebyshev polynomials

2015-04-06 Thread Tamas Papp
Thanks to everyone for the replies. I found that the excellent Chebyshev and Fourier Spectral Methods by J P Boyd discusses computation of derivatives in one of the appendices (A), suggesting 3 practical methods: (i) use the variable transformation in terms of the cosine, (ii) use Gegenbauer

[julia-users] Re: [ANN] JuliaIO and FileIO

2015-04-06 Thread Sebastian Good
Very interesting project. I've worked a little on problems like this in my projects and have found that filename extensions aren't always enough to distinguish filetypes. It's not uncommon to have to scan the first few (hundred) bytes looking for distinctive patterns, magic cookies, etc. to

[julia-users] Re: Error messages related to macros

2015-04-06 Thread Nehal Patel
Thanks Miles -- I had seen the brief discussion in 8701, but had totally missed 1334, and 6910 -- both are excellent resources that help me get my head around the issues involved. Nehal

Re: [julia-users] Re: updating an array

2015-04-06 Thread Stefan Karpinski
Can you describe what kind of a problem you are having? On Apr 6, 2015, at 10:51 AM, Jim Christoff j.christof...@gmail.com wrote: That was not it On Monday, April 6, 2015 at 9:05:16 AM UTC-4, Jim Christoff wrote: First, Julia is a great replacement for Octave and in most cases C. I have

[julia-users] Re: updating an array

2015-04-06 Thread Jim Christoff
That was not it On Monday, April 6, 2015 at 9:05:16 AM UTC-4, Jim Christoff wrote: First, Julia is a great replacement for Octave and in most cases C. I have used Octave for decades and Julia for a year or so. I still have problems making the conversions. Any assistance will be greatly

[julia-users] Re: updating an array

2015-04-06 Thread ggggg
I suspect you want ## generate next filter order if i==1 a[i] = g else a[i-1:-1:1] = a[i-1:-1:1]-g*a[i-1:-1:1] # this is my problem area* end a is first assigned as a Vector{Float64} of length p. Then you did a=g which assigns a as a Float64 (this

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Steven Sagaert
the one from the standard lib On Monday, April 6, 2015 at 4:01:00 PM UTC+2, Andreas Noack wrote: Which pca? 2015-04-06 6:53 GMT-07:00 Steven Sagaert steven@gmail.com javascript:: does pca() center the input output data or do you have to do that yourself?

[julia-users] Re: updating an array

2015-04-06 Thread Jim Christoff
Thank you very much for that clear description. That was the problem and it is producing the expected results. On Monday, April 6, 2015 at 10:53:40 AM UTC-4, g wrote: I suspect you want ## generate next filter order if i==1 a[i] = g else a[i-1:-1:1] =

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Andreas Noack
There is no pca in Julia Base 2015-04-06 9:16 GMT-07:00 Steven Sagaert steven.saga...@gmail.com: the one from the standard lib On Monday, April 6, 2015 at 4:01:00 PM UTC+2, Andreas Noack wrote: Which pca? 2015-04-06 6:53 GMT-07:00 Steven Sagaert steven@gmail.com: does pca() center

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Steven Sagaert
thanks! On Monday, April 6, 2015 at 6:43:54 PM UTC+2, Stefan Karpinski wrote: Looks like yes: https://github.com/JuliaStats/MultivariateStats.jl/blob/master/src/pca.jl On Mon, Apr 6, 2015 at 12:27 PM, Steven Sagaert steven@gmail.com javascript: wrote: I meant the one in

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Steven Sagaert
I meant the one in MultivariateStats package On Monday, April 6, 2015 at 6:19:51 PM UTC+2, Andreas Noack wrote: There is no pca in Julia Base 2015-04-06 9:16 GMT-07:00 Steven Sagaert steven@gmail.com javascript:: the one from the standard lib On Monday, April 6, 2015 at 4:01:00 PM

[julia-users] Re: Performance of random access sparse matrix algorithm

2015-04-06 Thread David Gleich
Making the change length(nzrange(P.A,u)) for du and dv fixes the issue. (Of course.) Is there any way to disable non-const global variables within a function? (Or warn when they are used?) David On Saturday, April 4, 2015 at 4:08:38 AM UTC-4, Tony Kelman wrote: This is an excellent use

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Stefan Karpinski
Looks like yes: https://github.com/JuliaStats/MultivariateStats.jl/blob/master/src/pca.jl On Mon, Apr 6, 2015 at 12:27 PM, Steven Sagaert steven.saga...@gmail.com wrote: I meant the one in MultivariateStats package On Monday, April 6, 2015 at 6:19:51 PM UTC+2, Andreas Noack wrote: There is

Re: [julia-users] does pca() center the data?

2015-04-06 Thread Stefan Karpinski
You may want to verify that since I looked very briefly at the code there. On Apr 6, 2015, at 12:47 PM, Steven Sagaert steven.saga...@gmail.com wrote: thanks! On Monday, April 6, 2015 at 6:43:54 PM UTC+2, Stefan Karpinski wrote: Looks like yes:

[julia-users] Re: updating an array

2015-04-06 Thread ggggg
Indexing of a Float64 is actually a bit inconsistent. It works for a single integer, but not for Ranges. *julia **a=4.5* *4.5* *julia **a[1]* *4.5* *julia **a[1:-1:1]* *ERROR: `getindex` has no method matching getindex(::Float64, ::StepRange{Int64,Int64})* *julia **a[1:1]* *ERROR: