[Haskell-cafe] Re: [Haskell] ANNOUNCE: An index-aware linear algebra library in Haskell

2006-04-16 Thread Alberto Ruiz
It is really counterintuitive! I will study carefully your library and the 
Implicit Configurations paper. Using static dimension checking we can write 
very solid code for matrix computations...

However, I don't know how to write some definitions. For instance, this is ok:

m = $(dAM [[1,2,3]])

but with:

x = [[1,2,3]] :: [[Double]]
m1 = $(dAM x)
m2 = listMat x

main = do
print m1
print m2

I get:

Vector/examples.hs:35:11:
GHC stage restriction: `x'
  is used in a top-level splice, and must be imported, not defined locally
In the first argument of `dAM', namely `x'
In the definition of `m1': m1 = $[splice](dAM x)

Vector/examples.hs:40:10:
Inferred type is less polymorphic than expected
  Quantified type variable `m' escapes
  Quantified type variable `n' escapes
  Expected type: (v (L m, L n) - w) - t
  Inferred type: (forall n1 m1.
  (ReflectNum n1, ReflectNum m1) =
  v (L m1, L n1) - w)
 - w
In the first argument of `print', namely `m2'
In the result of a 'do' expression: print m2


I would also like to create a matrix from a data file:

main = do
let m1 = $(dAM [[1,2],[3,4::Double]])
s - readFile data.txt
let list = read s :: [[Double]]
--let m2 = $(dAM list)
let m2 = listMat list
print $ m2 * trans m1

But I get a similar error. Perhaps I must provide information about the 
expected dimensions, but I don't know how to do it.

--
Alberto

On Saturday 15 April 2006 22:09, Frederik Eaton wrote:
 Yes, certainly... Otherwise the library would not be much use! If it
 seems counterintuitive, as it did to me at first, you should check out
 the Implicit Configurations paper, which uses modular arithmetic as
 an example. My version of their code is in

 http://ofb.net/~frederik/futility/src/Prepose.hs

 The function I mainly use is:

 reifyIntegral :: Integral a = a - (forall s. ReflectNum s = s - w) - w

 which turns an integral value into a type of the ReflectNum class
 which represents that value, and calls the provided polymorphic
 function with a dummy value (actually 'undefined') of that type; then
 returning the function's result.

 Frederik

 On Sat, Apr 15, 2006 at 06:14:44PM +0200, Alberto Ruiz wrote:
  On Friday 14 April 2006 17:02, Frederik Eaton wrote:
   An index-aware linear algebra library in Haskell
 
  Excellent work!
 
  Is it possible to create a vector or matrix whose size is not known at
  compile time?
 

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[Haskell-cafe] Re: [Haskell] ANNOUNCE: An index-aware linear algebra library in Haskell

2006-04-16 Thread Frederik Eaton
Hi Alberto,

Those are good questions, I've added some examples which hopefully
clarify the situation. Input and output of vectors is not a strong
point of the library, but I don't think there is a good alternative to
the way I do it.

  http://ofb.net/~frederik/futility/src/Vector/read-example.hs

(also, your example exposed some missing functionality. I've added
three new functions; in addition to listMat, now there are listMatCol,
listMatRow, and listMatSquare. Hopefully these should cover almost all
use cases.

  http://ofb.net/~frederik/futility/src/Vector/Base.hs
)

By the way, here is how I would download and run the thing, although
you seem to have figured it out:

$ wget http://ofb.net/~frederik/futility/futility-devel.tar.gz
$ tar -xvzf futility-devel.tar.gz
$ cd futility-devel/
$ ghc -fth --make Vector/read-example.hs -o read-example
$ ./read-example
# 11.0, 23.0; 14.0, 30.0; 15.0, 33.0; 18.0, 40.0 #
1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0
1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0
# 1.0, 5.0; 2.0, 6.0; 3.0, 6.0; 4.0, 7.0 #
# 11.0, 23.0; 14.0, 30.0; 15.0, 33.0; 18.0, 40.0 #
# -3.0, -5.0; -5.0, -7.0 #
# 7.0, 10.0; 15.0, 22.0 #

As for your questions:

 Vector/examples.hs:35:11:
 GHC stage restriction: `x'
   is used in a top-level splice, and must be imported, not defined locally
 In the first argument of `dAM', namely `x'
 In the definition of `m1': m1 = $[splice](dAM x)

This is a shortcoming of Template Haskell - it will not let you call a
function from a splice if that function is defined in the same file as
the splice. It should be possible to remove this shortcoming, but I
don't know what is planned.

 m2 = listMat x

This is not how listMat is used, see the example file above.

listMat takes a list of lists and a function, and passes the matrix
version of the list of lists to the function.

 I would also like to create a matrix from a data file:

See 'v3' in the example.

Cheers,

Frederik

On Sun, Apr 16, 2006 at 05:06:55PM +0200, Alberto Ruiz wrote:
 It is really counterintuitive! I will study carefully your library and the 
 Implicit Configurations paper. Using static dimension checking we can write 
 very solid code for matrix computations...
 
 However, I don't know how to write some definitions. For instance, this is ok:
 
 m = $(dAM [[1,2,3]])
 
 but with:
 
 x = [[1,2,3]] :: [[Double]]
 m1 = $(dAM x)
 m2 = listMat x
 
 main = do
 print m1
 print m2
 
 I get:
 
 Vector/examples.hs:35:11:
 GHC stage restriction: `x'
   is used in a top-level splice, and must be imported, not defined locally
 In the first argument of `dAM', namely `x'
 In the definition of `m1': m1 = $[splice](dAM x)
 
 Vector/examples.hs:40:10:
 Inferred type is less polymorphic than expected
   Quantified type variable `m' escapes
   Quantified type variable `n' escapes
   Expected type: (v (L m, L n) - w) - t
   Inferred type: (forall n1 m1.
   (ReflectNum n1, ReflectNum m1) =
   v (L m1, L n1) - w)
  - w
 In the first argument of `print', namely `m2'
 In the result of a 'do' expression: print m2
 
 
 I would also like to create a matrix from a data file:
 
 main = do
 let m1 = $(dAM [[1,2],[3,4::Double]])
 s - readFile data.txt
 let list = read s :: [[Double]]
 --let m2 = $(dAM list)
 let m2 = listMat list
 print $ m2 * trans m1
 
 But I get a similar error. Perhaps I must provide information about the 
 expected dimensions, but I don't know how to do it.
 
 --
 Alberto
 
 On Saturday 15 April 2006 22:09, Frederik Eaton wrote:
  Yes, certainly... Otherwise the library would not be much use! If it
  seems counterintuitive, as it did to me at first, you should check out
  the Implicit Configurations paper, which uses modular arithmetic as
  an example. My version of their code is in
 
  http://ofb.net/~frederik/futility/src/Prepose.hs
 
  The function I mainly use is:
 
  reifyIntegral :: Integral a = a - (forall s. ReflectNum s = s - w) - w
 
  which turns an integral value into a type of the ReflectNum class
  which represents that value, and calls the provided polymorphic
  function with a dummy value (actually 'undefined') of that type; then
  returning the function's result.
 
  Frederik
 
  On Sat, Apr 15, 2006 at 06:14:44PM +0200, Alberto Ruiz wrote:
   On Friday 14 April 2006 17:02, Frederik Eaton wrote:
An index-aware linear algebra library in Haskell
  
   Excellent work!
  
   Is it possible to create a vector or matrix whose size is not known at
   compile time?
  
 

-- 
http://ofb.net/~frederik/
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[Haskell-cafe] Re: [Haskell] ANNOUNCE: An index-aware linear algebra library in Haskell

2006-04-15 Thread Alberto Ruiz
On Friday 14 April 2006 17:02, Frederik Eaton wrote:
 An index-aware linear algebra library in Haskell

Excellent work!

Is it possible to create a vector or matrix whose size is not known at compile 
time? 

 - Due to the need to specify index types at some point, input of
 vectors is difficult. I have provided two functions in Fu.Vector.Base
 which should cover most of the cases:

 listVec :: Vector v e = [e] - (forall n . (ReflectNum n) = v (L n) - w)
 - w 
 listMat :: Vector v e = [[e]] - 
 (forall n m . (ReflectNum n, ReflectNum m) = v (L m, L n) - w) - w

 However, these aren't useful in interactive situations. So I have also
 provided some template-haskell routines

   http://ofb.net/~frederik/futility/src/Vector/Template.hs

 which can be used to instantiate vectors directly. For example:

(In examples.hs):

-- matrix with elements of type Double
v6 = trans $(dAM [[1,2,3,4]])

v7 = $(dAM [[1,0,0],[0,1,0],[0,0,1],[1,1,1]])

--
Alberto

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[Haskell-cafe] Re: [Haskell] ANNOUNCE: An index-aware linear algebra library in Haskell

2006-04-15 Thread Frederik Eaton
Yes, certainly... Otherwise the library would not be much use! If it
seems counterintuitive, as it did to me at first, you should check out
the Implicit Configurations paper, which uses modular arithmetic as
an example. My version of their code is in

http://ofb.net/~frederik/futility/src/Prepose.hs

The function I mainly use is:

reifyIntegral :: Integral a = a - (forall s. ReflectNum s = s - w) - w

which turns an integral value into a type of the ReflectNum class
which represents that value, and calls the provided polymorphic
function with a dummy value (actually 'undefined') of that type; then
returning the function's result.

Frederik

On Sat, Apr 15, 2006 at 06:14:44PM +0200, Alberto Ruiz wrote:
 On Friday 14 April 2006 17:02, Frederik Eaton wrote:
  An index-aware linear algebra library in Haskell
 
 Excellent work!
 
 Is it possible to create a vector or matrix whose size is not known at 
 compile 
 time? 
 
  - Due to the need to specify index types at some point, input of
  vectors is difficult. I have provided two functions in Fu.Vector.Base
  which should cover most of the cases:
 
  listVec :: Vector v e = [e] - (forall n . (ReflectNum n) = v (L n) - w)
  - w 
  listMat :: Vector v e = [[e]] - 
  (forall n m . (ReflectNum n, ReflectNum m) = v (L m, L n) - w) - w
 
  However, these aren't useful in interactive situations. So I have also
  provided some template-haskell routines
 
http://ofb.net/~frederik/futility/src/Vector/Template.hs
 
  which can be used to instantiate vectors directly. For example:
 
 (In examples.hs):
 
 -- matrix with elements of type Double
 v6 = trans $(dAM [[1,2,3,4]])
 
 v7 = $(dAM [[1,0,0],[0,1,0],[0,0,1],[1,1,1]])
 
 --
 Alberto
 

-- 
http://ofb.net/~frederik/
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