Hi,
I wouldn't call this a bug, overlapping instances
and in particular the combination with functional dependencies
are something which is not well studied yet.
Hence, GHC is very conservative here.
I feel like you, this program should work.
As you correctly point out, there's a conflict among
Martin's dead right. GHC uses a less sophisticated mechanism to do
matching when it's thinking about functional dependencies than when it's
doing straight instance matching. Maybe something cleverer for fundeps
would make sense, as you point out. I hadn't thought of that before;
it's a good
Simon's dead right, too :) The issue raised here is of general nature and
doesn't depend on the particular (syntactic) formalism used to specify
type dependencies (let it be FDs, ATs,...). The consequence is that
instances and type dependencies are closer linked to each other
then one might think
The server is working again.
On Thursday 07 July 2005 20:58, Alberto Ruiz wrote:
I' sorry, our web server is temporarily down :-(
http://dis.um.es/~alberto/hmatrix/matrix.html
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On Fri, 8 Jul 2005, Alberto Ruiz wrote:
The server is working again.
On Thursday 07 July 2005 20:58, Alberto Ruiz wrote:
I' sorry, our web server is temporarily down :-(
http://dis.um.es/~alberto/hmatrix/matrix.html
I would remove the 'matrix' portions of the function names, since
On Thu, 7 Jul 2005, Alberto Ruiz wrote:
Hello! Thank you very much for all your suggestions. A new version of the
library can be found at:
http://dis.um.es/~alberto/hmatrix/matrix.html
If the Matrix type would be parametrised then Matrix.fromBlocks could use
a more natural indexing.
So is sharing already implemented in Haskell ?
Do i have to use where clause to implement the sharing ?
Thanks a lot for your help
Cheers
To understand cyclic structures it is useful to think of graph
reduction, because these graphs allow us to conveniently represent
sharing between
On Thu, Jul 07, 2005 at 03:08:50PM +0200, Henning Thielemann wrote:
On Thu, 7 Jul 2005, David Roundy wrote:
On Tue, Jul 05, 2005 at 08:17:58PM +0200, Henning Thielemann wrote:
The example, again: If you write some common expression like
transpose x * a * x
then both the human
Henning Thielemann wrote:
My objections to making everything a matrix were the objections I sketched
for MatLab.
The example, again: If you write some common expression like
transpose x * a * x
Which just goes to show why haskell limits the '*' operator to
multiplying the same types. Keep
On Thu, 7 Jul 2005, David Roundy wrote:
On the other hand, this is sort of a silly debate, since the API *I*
want is a subset of the API *you* want.
The API you want is certainly not just a subset of what I want. E.g. the
singular value decomposition in your favorite API will probably return
On Fri, 8 Jul 2005, Alberto Ruiz wrote:
The server is working again.
On Thursday 07 July 2005 20:58, Alberto Ruiz wrote:
I' sorry, our web server is temporarily down :-(
http://dis.um.es/~alberto/hmatrix/matrix.html
I would also prefer a vector of complex numbers for the FFT
Henning Thielemann wrote:
Let me elaborate on that:
In some cases putting vectors as columns into a matrix then applying a
matrix operation on this matrix leads to the same like to 'map' a
matrix-vector operation to a list of vectors. But in other cases (as the
one above) this is not what you
On Fri, 8 Jul 2005, Keean Schupke wrote:
Henning Thielemann wrote:
My objections to making everything a matrix were the objections I sketched
for MatLab.
The example, again: If you write some common expression like
transpose x * a * x
Which just goes to show why haskell limits the
On Fri, 8 Jul 2005, Keean Schupke wrote:
Okay, this approach is starting to make sense to me... I can see now
that Vectors are a different type of object to Matrices. Vectors
represent points in N-Space and matrices represent operations on those
points
That's what I wanted to express.
Henning Thielemann wrote:
I'm excited if your code gets swamped by conversions between Double and
Matrix then. I really plead for representing everything with strings, this
is the most simple and most flexible solution! :-]
Surely its a case of balancing the advantage of type safety against
Henning Thielemann wrote:
Do you mean
[x,y,z,1] * [[1,0,0,0],[0,1,0,0],[0,0,1,0],[dx,dy,dz,dw+1]]
?
Erm, yes thats what I meant ... but you obviously got the point.
but how is this different from adding vectors? If we allow vector
addition then we no longer have the nice separation
On Fri, Jul 08, 2005 at 03:33:16PM +0200, Henning Thielemann wrote:
On Thu, 7 Jul 2005, David Roundy wrote:
On the other hand, this is sort of a silly debate, since the API *I*
want is a subset of the API *you* want.
The API you want is certainly not just a subset of what I want. E.g.
Is a matrix is a linear operation on a vector, does it not make sense to
define matrix applicaion:
mapply :: Matrix - Vector - Vector
Then you can define say:
rotate90 = mapply rotationMatrix90
v' = rotate90 v
Keean.
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On Fri, 8 Jul 2005, Keean Schupke wrote:
Henning Thielemann wrote:
Do you mean
[x,y,z,1] * [[1,0,0,0],[0,1,0,0],[0,0,1,0],[dx,dy,dz,dw+1]]
?
Erm, yes thats what I meant ... but you obviously got the point.
but how is this different from adding vectors? If we allow vector
addition
Henning Thielemann wrote:
In general a vector need not to be a linear operator. You talked about
vector translation, translation is not a linear operator. You gave some
process to map the problem to somewhere, where it becomes a linear
operator. Other people said that the scalar product with a
On Fri, 8 Jul 2005, David Roundy wrote:
I don't particularly care what API you use for svd, since it's trivial to
convert from one API to the other. It's matrix arithmetic I care about,
since that's the complicated part of the API.
Of course I want to use the results of more complicated
On Fri, 8 Jul 2005, Keean Schupke wrote:
Is a matrix is a linear operation on a vector,
It _is_ not a linear map, but it is a canonical representation of a linear
map.
does it not make sense to define matrix applicaion:
mapply :: Matrix - Vector - Vector
Then you can define say:
On Fri, 8 Jul 2005, Keean Schupke wrote:
So the linear operator is translation (ie: + v)... effectively 'plus'
could be viewed as a function which takes a vector and returns a matrix
(operator)
(+) :: Vector - Matrix
Since a matrix _is_ not a linear map but only its representation,
Henning Thielemann wrote:
On Fri, 8 Jul 2005, Keean Schupke wrote:
So the linear operator is translation (ie: + v)... effectively 'plus'
could be viewed as a function which takes a vector and returns a matrix
(operator)
(+) :: Vector - Matrix
Since a matrix _is_ not a linear map
Henning Thielemann wrote:
does it not make sense to define matrix applicaion:
mapply :: Matrix - Vector - Vector
Then you can define say:
rotate90 = mapply rotationMatrix90
v' = rotate90 v
... that's what I said about mulVec.
I guess that means we agree...
Keean.
Another question, it's said in the book that using cyclic structure (like
ones = 1:ones) , the list would be represented by a fixed amount of memory.
Does it mean [1,1,1..] only occupy one cell of memory ?
How about in take 100 [1,1,...] ?
From: Dinh Tien Tuan Anh [EMAIL
On Fri, 8 Jul 2005, Dinh Tien Tuan Anh wrote:
Another question, it's said in the book that using cyclic structure (like
ones = 1:ones) , the list would be represented by a fixed amount of memory.
Does it mean [1,1,1..] only occupy one cell of memory ?
How about in take 100
On Fri, 8 Jul 2005, Keean Schupke wrote:
Henning Thielemann wrote:
does it not make sense to define matrix applicaion:
mapply :: Matrix - Vector - Vector
Then you can define say:
rotate90 = mapply rotationMatrix90
v' = rotate90 v
... that's what I said about
On Fri, 8 Jul 2005, Keean Schupke wrote:
Henning Thielemann wrote:
On Fri, 8 Jul 2005, Keean Schupke wrote:
So the linear operator is translation (ie: + v)... effectively 'plus'
could be viewed as a function which takes a vector and returns a matrix
(operator)
(+) :: Vector -
On Friday 08 July 2005 17:46, Henning Thielemann wrote:
Vectors can be used and abused for many things but
an object which can be called a vector (because of its ability of to
be added and to be scaled) is not a linear operator itself and does
not naturally represent one.
At least for finite
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