Fwd: Re: [Toon-members] std::vector overload to use with TooN ( Dynamic Matrix assembling)

[Gabriel Nützi]

(sorry, wrong email)

Hello!

I have no the following problem with TooN:

I am on Ubuntu 10, when I compile the follwing code:

std::vector< Vector<6,double> > A;
A.assign(7,makeVector(1,2,3,4,5,6));
Matrix<Dynamic,Dynamic,double,Reference::ColMajor> B(&(A[0][0]),6,7);
cout << B<<endl;

Output B:
1 1 1 1 1 1 1
2 2 2 2 2 2 2
3 3 3 3 3 3 3
4 4 4 4 4 4 4
5 5 5 5 5 5 5
6 6 6 6 6 6 6

This is fine!
but replace the first line with : 

std::vector< Vector<Dynamic,double> > A;

Output B:
1 0.145192 2.0225e-316 1 6.92627e-310 0 0
2 3.21143e-322 2.0223e-316 0 6.92619e-310 0 1.8941e-316
3 3.17437e-320 0 0 0 0 1.30354e-76
4 2.02236e-316 3.21143e-322 0 1.754e+97 0 0
5 1.95573e-316 0 0 0 0 7.72779e+228
6 2.02102e-316 0 1.9812e-321 0 2.122e-314 0

Which is completey nonsense, only because the definition of std:vector is Dynamic?  Why is this like that (on OS X this does not happen?)

Does anyone has a clue why this is that way?

Thanks in Advance!!!

Gabriel


-------- Original-Nachricht --------
> Datum: Sun, 23 May 2010 13:49:18 +0100 (BST)
> Von: "E. Rosten" <address@hidden>
> An: "Gabriel Nützi" <address@hidden>
> CC: address@hidden
> Betreff: Re: [Toon-members] std::vector overload to use with TooN ( Dynamic Matrix assembling)

> On Sat, 22 May 2010, Gabriel Nützi wrote:
>
> > Hello all
> >
> > I have a question , and I don't know how to solve this as good as
> possible:
> >
> > I have an iteration in which I always assemble new Matrices (m x 7)
> >  dynamically, so I do not know how big they become in each iteration,
> > the size m varies,
>
>
> I knew this problem would come up sooner or later. The best current
> solution is to use a std::vector along with wrapMatrix (as suggested by an
> earlier email).
>
> The bect actual solution, I think is to write a Resizable allocator for
> Matrix. I think we actually want 2 allocators: one with resizable rows and
> one with resizable columns, and with methods to append/resize only the
> relavent dimension.
>
> There may also be a case for generically resizable matrices, bit it is not
> as clear cut.
>
> -Ed
>
>
>
> > Is there a way of realizing this either with TooN or with overloads in
> std::vector< Vector<7> >   efficiently
> > The only way I can push rows in my Matrix dynamically is with
> std::vector ....
> >
> > I was searching for a way to make this compatible with TooN and
> efficient (I dont want to copy heaps of data around) ? But I ve come up so far only
> with a overload in std::vectors
> >
> > wrote the  fallowing overload:
> >
> >
> > //Specialized Template vor Vector<>
> > template <int N1, int N2, typename P, typename B>
> > Vector<Dynamic,P,B> operator*(const std::vector<Vector<N1,P,B> >& x,
> Vector<N2,P,B> &y)
> > {
> >     Vector<Dynamic,P,B> v(x.size());
> > v= Zeros;
> > for (int m=0; m< x.size();m++) {
> > for (int n=0; n<y.size(); n++) {
> > v[m] += x[m][n] * y[n];
> > }
> > }
> > return v;
> > }
> >
> >
> >
> > Does anyone know why the error happens here:
> >
> > vector<Vector<3> > A;
> > A.assign(3,makeVector(1,2,3));
> > Vector<> a = makeVector(2,2,2);
> > Vector<> c = A * a ;
> > Vector<> b = A * ( A * a );   // ERRRRROOOOOORRRRRR  (but why))
> >
> >
> > Would be very helpful if anyone could tell me how I should do this to
> make it efficient , and why this ERROR happens?
> >
> >
> > Thanks alot for your support!
> >
> > Gabriel
> >
> >
> >
>
> --
> (You can't go wrong with psycho-rats.)(http://mi.eng.cam.ac.uk/~er258)
>
> /d{def}def/f{/Times s selectfont}d/s{11}d/r{roll}d f 2/m{moveto}d -1
> r 230 350 m 0 1 179{ 1 index show 88 rotate 4 mul 0 rmoveto}for/s 12
>      d f pop 235 420 translate 0 0 moveto 1 2 scale show showpage

-------- Original-Nachricht --------
Datum: Sun, 23 May 2010 13:49:18 +0100 (BST)
Von: "E. Rosten" <address@hidden>
An: "Gabriel Nützi" <address@hidden>
CC: address@hidden
Betreff: Re: [Toon-members] std::vector overload to use with TooN ( Dynamic Matrix assembling)

On Sat, 22 May 2010, Gabriel Nützi wrote:

> Hello all
>
> I have a question , and I don't know how to solve this as good as possible:
>
> I have an iteration in which I always assemble new Matrices (m x 7)
>  dynamically, so I do not know how big they become in each iteration,
> the size m varies, 


I knew this problem would come up sooner or later. The best current
solution is to use a std::vector along with wrapMatrix (as suggested by an
earlier email).

The bect actual solution, I think is to write a Resizable allocator for
Matrix. I think we actually want 2 allocators: one with resizable rows and
one with resizable columns, and with methods to append/resize only the
relavent dimension.

There may also be a case for generically resizable matrices, bit it is not
as clear cut.

-Ed



> Is there a way of realizing this either with TooN or with overloads in std::vector< Vector<7> >   efficiently
> The only way I can push rows in my Matrix dynamically is with std::vector ....
>
> I was searching for a way to make this compatible with TooN and efficient (I dont want to copy heaps of data around) ? But I ve come up so far only with a overload in std::vectors
>
> wrote the  fallowing overload:
>
>
> //Specialized Template vor Vector<>
> template <int N1, int N2, typename P, typename B>
> Vector<Dynamic,P,B> operator*(const std::vector<Vector<N1,P,B> >& x, Vector<N2,P,B> &y)
> {
>     Vector<Dynamic,P,B> v(x.size());
> v= Zeros;
> for (int m=0; m< x.size();m++) {
> for (int n=0; n<y.size(); n++) {
> v[m] += x[m][n] * y[n];
> }
> }
> return v;
> }
>
>
>
> Does anyone know why the error happens here: 
>
> vector<Vector<3> > A;
> A.assign(3,makeVector(1,2,3));
> Vector<> a = makeVector(2,2,2);
> Vector<> c = A * a ;
> Vector<> b = A * ( A * a );   // ERRRRROOOOOORRRRRR  (but why))
>
>
> Would be very helpful if anyone could tell me how I should do this to make it efficient , and why this ERROR happens?
>
>
> Thanks alot for your support!
>
> Gabriel
>
>
>

--
(You can't go wrong with psycho-rats.)(http://mi.eng.cam.ac.uk/~er258)

/d{def}def/f{/Times s selectfont}d/s{11}d/r{roll}d f 2/m{moveto}d -1
r 230 350 m 0 1 179{ 1 index show 88 rotate 4 mul 0 rmoveto}for/s 12
d f pop 235 420 translate 0 0 moveto 1 2 scale show showpage

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