Re: [Haskell-cafe] timing question

Thanks for all the advises so far. Ok, here's my monster that need to be timed in order to make a comparison: (it's about the control digit of SEDOL numbers http://en.wikipedia.org/wiki/SEDOL ): knip _ [] = Nothing knip k xs = Just (splitAt k xs) ip xs = sum . zipWith (*) xs an =

Re: [Haskell-cafe] timing question

seqList rwhnf(map f ry) () (4.48 secs, 833668720 bytes) *Main seqList rwhnf(map f ry) () (3.18 secs, 627071612 bytes) *Main Arie Groeneveld schreef: Thanks for all the advises so far. Ok, here's my monster that need to be timed in order to make a comparison: (it's about the control digit

[Haskell-cafe] timing question

Suppose I've: f = map g I want to know how much time it takes (interpreted mode) to fully process list xs (at least 1e6 elements) with function g. Is it sufficient to execute: *Main last . f $ xs result (x.xx secs, yyy bytes) Are there any hidden difficulties involved? Reason is:

Re: [Haskell-cafe] timing question

Sorry, should go the forum. Ok, thanks. In this case the list consists of 6-digit alphanumeric codes. So doing something like: foldl1 (\x y - g y) xs will do the job? =@@i Bulat Ziganshin schreef: Hello Arie, Sunday, August 3, 2008, 1:56:43 PM, you wrote: *Main last . f $ xs this way

Re: [Haskell-cafe] Folding Integrals

Reinier Lamers schreef: printint :: Int - [Char] printint = map chr . map (+0x30) . reverse . map (`mod` 10) . takeWhile (0) . iterate (`div`10) Most of the time I use this: digits :: Integer - [Int] digits = map (flip(-)48.ord) . show Regards =@@i

Re: [Haskell-cafe] Geometry

Steve Schafer wrote: x = a - sqrt(a^2 - b^2) I don't know offhand if there's a straightforward way to arrive at this result without using trigonometry. Here you go, though with a slightly different result (same as Joel Koerwer): a^2=(b^2)/4+(a-x)^2 (Pythagoras) solving x: -- x(1,2) = a

Re: [Haskell-cafe] Geometry

Correction stefan a b = a - a * sqrt (1 - b*b / a*a) should be: stefan a b = a - a * sqrt (1 - b*b / (a*a)) *Main stefan 10 8 4.0 (0.01 secs, 524896 bytes) Thanks @@i ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org

[Haskell-cafe] Style

Hi, I defined several functions for calculating the number of trailing zero's of n! tm = sum . takeWhile(0) . iterate f . f where f = flip div 5 tm1 n = sum . takeWhile(0) . map (div n . (5^)) $ [1..] tm2 n = sum . takeWhile(0) . map (div n) $ iterate ((*)5) 5 tm3 = sum . takeWhile(0) .

Re: [Haskell-cafe] Style

Bjorn Bringert wrote: Here's a much more inefficient version, but it has the merit of being very easy to understand: tm_silly n = length $ takeWhile (=='0') $ reverse $ show $ product [1..n] You're rigth. I came up with that one too the first time. But for large value's of n it

Re: [Haskell-cafe] Style

Thanks for all the instructive replies and alternatives! Learned a bit more in terms of feeling about style and improvement of some of the functions: f.e. 'killing' the 'where' in my number one choice. Thanks @@i ___ Haskell-Cafe mailing list

Re: [Haskell-cafe] Style

Henning Thielemann wrote: tm4 = sum . takeWhile(0) . tail . iterate (flip div 5) FWIW: as a result of all this I learned to write this as: tm41 = sum . takeWhile(0) . tail . iterate (`div` 5) @@i ___ Haskell-Cafe mailing list

[Haskell-cafe] expension of fractions

Hi, I don't know if this is the right place to post this, but here I go. I translated a BC-program found on the home page of Keith Matthews, http://www.numbertheory.org/keith.html. It's about the expension of a (not necessarily reduced) fraction m/n in base b. Looking at the result of my

Re: [Haskell-cafe] Time consumption nub

I tried this version, however nsortBy cmp l = mergesort compare l should be: nsortBy cmp l = mergesort cmp l Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Time consumption nub

I tried this version, however nsortBy cmp l = mergesort compare l should be: nsortBy cmp l = mergesort cmp l Thanks Sorry, with this version I meant: nsort l = mergesort compare l nsortBy cmp l = mergesort compare l mergesort :: (a - a - Ordering) - [a] - [a] mergesort cmp =

Re: [Haskell-cafe] Time consumption nub

Miguel Mitrofanov wrote: AG Wondering about time space consuming: 'nub' vs 'map AG head.group.sort' Prelude :t Data.List.nub Data.List.nub :: (Eq a) = [a] - [a] Prelude :t Data.List.sort Data.List.sort :: (Ord a) = [a] - [a] nub uses less information than sort, so it MUST be slower. Ok,

[Haskell-cafe] 1d-rubik

Hi all, I read this on the J -programming forum http://www.jsoftware.com/pipermail/programming/2007-June/007004.html Maybe of interest, especially the part of generating the subgroup or composing a more intelligent solver. quote I found an interesting game, as found on Andrew Nikitin's