[Haskell-cafe] All binary strings of a given length
Hi - How can I generate all binary string of a given length? The type signature would something like - genbin :: Int - [String] For example genbin 2 would give [00,11,01,10] and genbin 3 would give [000,001,010,011,100,101,110,111] etc.. thanks.. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: All binary strings of a given length
Amazing, will never find this in any other languagw. But ghci crashes for bigger input. Like genbin 20. How to scale this function? On 10/15/10, Eugene Kirpichov ekirpic...@gmail.com wrote: Here's why it works: genbin 3 = replicateM 3 01 = (unfold replicateM) do x1 - 01; x2 - 01 ; x3 - 01; return [x1,x2,x3] = your desired result (enumerate all combinations of x1,x2,x3 with each being 0 or 1). 2010/10/15 Eugene Kirpichov ekirpic...@gmail.com: genbin = flip replicateM 01 2010/10/15 rgowka1 rgow...@gmail.com: Hi - How can I generate all binary string of a given length? The type signature would something like - genbin :: Int - [String] For example genbin 2 would give [00,11,01,10] and genbin 3 would give [000,001,010,011,100,101,110,111] etc.. thanks.. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Eugene Kirpichov Senior Software Engineer, Grid Dynamics http://www.griddynamics.com/ -- Eugene Kirpichov Senior Software Engineer, Grid Dynamics http://www.griddynamics.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: All binary strings of a given length
Thanks Daniel.
But genbin 32 gives an empty list.. works till 31.
On Fri, Oct 15, 2010 at 9:05 AM, Daniel Gorín dgo...@dc.uba.ar wrote:
I expect this one to run in constant space:
import Data.Bits
genbin :: Int - [String]
genbin n = map (showFixed n) [0..2^n-1::Int]
where showFixed n i = map (bool '1' '0' . testBit i) [n-1,n-2..0]
bool t f b = if b then t else f
Daniel
On Oct 15, 2010, at 9:43 AM, Eugene Kirpichov wrote:
Actually my ghci doesn't crash for genbin 25 (haven't tried further),
though it eats quite a bit of memory.
How are you going to use these bit strings? Do you need all of them at once?
2010/10/15 Aleksandar Dimitrov aleks.dimit...@googlemail.com:
On Fri, 15 Oct 2010 14:34:42 +0200, rgowka1 rgow...@gmail.com wrote:
Amazing, will never find this in any other languagw. But ghci crashes
for bigger input. Like genbin 20. How to scale this function?
Well, scaling this isn't really possible, because of its complexity. It
generates all permutations of a given string with two states for each
position. In regular languages, this is the language {1,0}^n, n being the
length of the string. This means that there are 2^n different strings in the
language. For 20, that's already 1048576 different Strings! Strings are
furthermore not really the best way to encode your output. Numbers (i.e.
bytes) would be much better. You could generate them, and only translate
into strings when needed.
HTH,
Aleks
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
Eugene Kirpichov
Senior Software Engineer,
Grid Dynamics http://www.griddynamics.com/
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Help to create a function to calculate a n element moving average ??
Type signature would be Int - [Double] - [(Double,Double)] Any thoughts or ideas on how to calculate a n-element moving average of a list of Doubles? Let's say [1..10]::[Double] what is the function to calculate the average of the 3 elements? [(1,0),(2,0),(3,2),(4,3)] :: [(Double,Double)] (1,0) the average is zero as the length is less than 3 (2,0) the average is zero as the length is less than 3 (3,2) the average is (1+2+3)/3 = 2 (4,3) the average is (2+3+4)/3 = 9 .. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Candlestick charts
Hi - What are the libraries to use in Haskell to generate a stock candlestick chart like http://stockcharts.com/h-sc/ui?s=SPYp=Db=5g=5id=p05007254056 I will use Finance-Quote-Yahoo to get the quote data from Yahoo. thanks for all your help. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Candlestick charts
Can I just do cabal install gnuplot or should I use darcs to get the candles version.. On Sat, Sep 25, 2010 at 8:03 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: On Sat, 25 Sep 2010, rgowka1 wrote: Hi - What are the libraries to use in Haskell to generate a stock candlestick chart like http://stockcharts.com/h-sc/ui?s=SPYp=Db=5g=5id=p05007254056 I will use Finance-Quote-Yahoo to get the quote data from Yahoo. You might try the gnuplot package as interface to the gnuplot program. There was already someone who wanted to plot candle sticks: http://projects.haskell.org/pipermail/gnuplot/2010-April/09.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Candlestick charts
I am trying to compile demo.hs, but keep getting the error that Paths_gnuplot could not be found. What/where is paths_gnuplot?? Sorry, I am still a beginner.. On Sat, Sep 25, 2010 at 8:48 AM, Henning Thielemann lemm...@henning-thielemann.de wrote: On Sat, 25 Sep 2010, rgowka1 wrote: Can I just do cabal install gnuplot or should I use darcs to get the candles version.. The Hackage version should be up to date now. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] xemacs newbie question - haskell mode
HI - I have been struggling to get the Xemacs recognize hs file. I have installed the Haskell-mode.. However I keep getting the message File mode specification error: (wrong-number-of-arguments require 3).. How do I go about fixing this?? Many thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
