http://julia.readthedocs.org/en/release-0.3/manual/faq/#i-passed-an-argument-x-to-a-function-modified-it-inside-that-function-but-on-the-outside-the-variable-x-is-still-unchanged-why
http://www.johnmyleswhite.com/notebook/2014/09/06/values-vs-bindings-the-map-is-not-the-territory/ On Monday, June 8, 2015 at 9:28:16 AM UTC-7, bernhard wrote: > > All > > I would like to sort a vector according to a given index (or permutation). > I understand that the code below produces a false (last evaluation below) > due to the fact that the function creates a local copy of x. > How can I modify my function such that x is in sorted differently (i.e. > such that the argument is modified)? > Thank you in advance. > > > x=rand(5) > anothervector=rand(5) > > mypermutation=sortperm(x) > > function change_order!(x,srt) > x=x[srt] > nothing > end > > before=copy(anothervector) > change_order!(anothervector,mypermutation) > > before==anothervector[mypermutation] #false > > before==anothervector #true, this should be false > before[mypermutation]==anothervector #false, this should be true >
