[Haskell-beginners] 2D rectanlge array type

[Nathan Hüsken]

Hey,

Thanks for the tips. But when the lists get really long, this methods 
seems to be very cumbersome, or am I misssing something?

Regards,
Nathan

Am 9/12/2013 9:09 PM, schrieb Nick Vanderweit:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
> Hi Nathan,
>
> It is actually possible (and pretty easy) to encode natural numbers as
> types [1]. You could create a sequence type which is parameterized
> over both the element type and the number of contained elements.
>
>
> Nick
>
> [1] http://www.haskell.org/haskellwiki/Type_arithmetic
>
> On 09/12/2013 10:28 AM, Nathan Hüsken wrote:
>> Hey,
>>
>> I am experimenting with machine learning in haskell. For training
>> a model, I need to input a list of features. A features itself is a
>> set of floating point numbers. So my training data has the type:
>>
>> [Feature]
>>
>> What I am wondering is which type I should use for Feature. As I
>> said, it is a set of floats. But every feature must have exactly
>> the same number of floats. I could use
>>
>> type Feature = [Float]
>>
>> but that would not ensure that every feature has the same number
>> of flaots. I could use tuples
>>
>> type Feature = (Float,Float,Float,Float,Float ...)
>>
>> The number of features varies from application to application. And
>> I do not know how to encode that with tuples. Also the number of
>> features can get very big (in extreme cases up to ~1000, in normal
>> cases ~100).
>>
>> How would you do that?
>>
>> Thanks! Nathan
>>
>>
>> _______________________________________________ Beginners mailing
>> list Beginners at haskell.org
>> http://www.haskell.org/mailman/listinfo/beginners
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.12 (GNU/Linux)
> Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/
>
> iF4EAREIAAYFAlIyEVMACgkQJlmDAU/j7BAI1AEAqLQLSyMYwJfzWK5LoNlv5OFK
> EYI5cxR8sZU3upZQYoQA/3Tk8iNW3a68RiDxF1nSfgo/ENhjfqTbxhFSo5M46y49
> =wUuu
> -----END PGP SIGNATURE-----