[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Toon-members] std::vector overload to use with TooN ( Dynamic Matri

From: E. Rosten
Subject: Re: [Toon-members] std::vector overload to use with TooN ( Dynamic Matrix assembling)
Date: Sun, 23 May 2010 13:49:18 +0100 (BST)
User-agent: Alpine 2.00 (LSU 1167 2008-08-23)

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.


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> 
    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;
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!


(You can't go wrong with psycho-rats.)(

/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

reply via email to

[Prev in Thread] Current Thread [Next in Thread]