Check out my blog article from last year and search for the spot where I describe the "priming the pump" trick: http://programming-puzzler.blogspot.com/2012/11/coin-change-kata-in-racket-and-clojure.html
If the simplest way to write the solution to your problem is to use a top-down form of memoization, you can still avoid blowing the stack by running it in a bottom-up fashion a la traditional dynamic programming. On Sun, Sep 22, 2013 at 8:19 AM, John Lawrence Aspden < aspd...@googlemail.com> wrote: > Hi Guys, > > I'm trying to memoize a fairly complicated double recursion, and it's > blowing stack after not terribly many calls. > > I've reduced the problem to a simple test case, summing from 1 to n : > > user=> (clojure-version) > "1.5.1" > user=> (def gauss-recurse (fn [n] (if (< n 1) 0 (+ n (gauss-recurse (dec > n)))))) > #'user/gauss-recurse > user=> (gauss-recurse 3500) > 6126750 > user=> (def gauss-memoized (memoize (fn [n] (if (< n 1) 0 (+ n > (gauss-memoized (dec n))))))) > #'user/gauss-memoized > user=> (gauss-memoized 160) > > StackOverflowError clojure.lang.RT.boundedLength (RT.java:1654) > user=> > > > Does anyone know why this would happen? Do I just have to give up on > memoization and find another way to do dynamic programming? > > Cheers, John. > > -- > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
