initialize variable as global

[MCJamaica]

Hello everybody.
I try to handle a matrix in my programm. I still reached to declare this matrix as a two dimensional vector in a testprogramm as follows:

vector < vector <double> > B(Num_Rows);  

for( int i = 0; i < Num_Rows; i++ )
       B[i].resize(Num_Col);

Everything works there fine and I can call the matrix by B[i][j]. For my main programm, I right now need to declare this matrix B globally (without any knowledge of the size of rows and cols). And afterwards, somewhere inside the programm I read out the Num_Rows and Num_Cols and have to change the size and fill in entries.

My main question is how to declare this matrix B global without knowing the final size.

I would be happy if you can help me.

[MCJamaica]

hey guys...
nobody there who can help me?

[Moschops]

You don't need to know the final size. You can declare it with a size of 1 and then resize it later.

[Caligulaminus]

vector<vector<double> > B;

Edit: too late again :|