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 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 :
>>> On Fri, 15 Oct 2010 14:34:42 +0200, rgowka1 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
>>> ___
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>>>
>>
>>
>>
>> --
>> Eugene Kirpichov
>> Senior Software Engineer,
>> Grid Dynamics http://www.griddynamics.com/
>> ___
>> Haskell-Cafe mailing list
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>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>
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[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 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 : >> genbin = flip replicateM "01" >> >> 2010/10/15 rgowka1 : >>> 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
[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] 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
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 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
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 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=SPY&p=D&b=5&g=5&id=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
[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=SPY&p=D&b=5&g=5&id=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
[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
