Read Christophe's post about multi-dim arrays. Reflection is getting in the way here.
On Wed, Nov 25, 2009 at 2:55 AM, Amnon <amnon.hei...@gmail.com> wrote: > Hi Konrad, > In the original post, I put in the code, it was removed by the post > editor. > The way I wanted it implement, I have the main in java (gui and > stuff). I create a 3D array in java, it's an int array (i.e. int arr[] > [][] ) and call with that array to clojure. > > It can be done in java at least 3 orders of magnitude faster so I'm > sure there is something I'm doing wrong. > I'll appreciate any suggestion. > Thanks, > Amnon > > I've squeezed my example into two functions: > > (defn light [arr x y] > (+ (aget arr x y 0) (aget arr x y 1) (aget arr x y 2)) > ) > > (defn grey [arr] > (dotimes [x (length arr)] > (dotimes [y (alength (aget arr 0))] > (let [lg (int (/ (light arr x y) 3))] > (aset arr x y 0 lg) > (aset arr x y 1 lg) > (aset arr x y 2 lg) > )))) > > > > > > On Nov 24, 8:35 pm, Konrad Hinsen <konrad.hin...@fastmail.net> wrote: > > On 24 Nov 2009, at 17:30, Amnon wrote: > > > > > I hope it's not the billion time you get the question. > > > I wanted to use clojure for image processing. I have a 3 dimensional > > > array I'm passing to clojure from java. > > > I then loop on the array to manipulate it. > > > Even the simplest task takes about half a minutes (I expected it to be > > > over in less than a second) > > > > Could you give some more details? For example, what is the Java class > > you use for the 3D arrays? How are you accessing it from Clojure? How > > do you do the loops? How do you create the destination array, and how > > do you fill it with the grey-scale values? I suspect that many of > > these steps could be optimized, but it's hard to say without knowing > > how your current code works. > > > > Konrad. > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com<clojure%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
