Ich will folgendes machen:

//hier fängt die Methode an...    
int mix_matrix[vector_dimension][number_of_patches]; //column vector merged in a matrix

//mach hier was...

return mix_matrix;

Als Fehler erhalte ich in der Konsole:

g++ -c -pipe -fno-strict-aliasing -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt/mkspecs/default -I. -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include -I. -I. -I. -o PatchGenerator.o PatchGenerator.cpp
PatchGenerator.cpp: In member function ‘int* PatchGenerator::transform_patches_to_vectors_and_merge_to_matrix(std::vector<QImage*, std::allocator<QImage*> >*, int)’:
PatchGenerator.cpp:26: error: cannot convert ‘int (*)[(((unsigned int)(((int)vector_dimension) - 1)) + 1u)][(((unsigned int)(((int)number_of_patches) - 1)) + 1u)]’ to ‘int*’ in return
make: *** [PatchGenerator.o] Fehler 1

int* PatchGenerator::transform_patches_to_vectors_and_merge_to_matrix( vector<QImage*>* patches , int rect_size ) {

int** PatchGenerator::transform_patches_to_vectors_and_merge_to_matrix( vector<QImage*>* patches , int rect_size ) {

    int mix_matrix[vector_dimension][number_of_patches]; //column vector merge in a matrix
//mach hier was....

    return mix_matrix;
}

Ich erhalte wieder den Fehler:

PatchGenerator.cpp: In member function ‘int** PatchGenerator::transform_patches_to_vectors_and_merge_to_matrix(std::vector<QImage*, std::allocator<QImage*> >*, int)’:
PatchGenerator.cpp:22: error: cannot convert ‘int (*)[(((unsigned int)(((int)number_of_patches) - 1)) + 1u)]’ to ‘int**’ in return
make: *** [PatchGenerator.o] Fehler 1

Also auf deine Art kannst du kein dynamisches Array anlegen.

Mach es so:

int* a;
a = new int[x]; jetzt kann x auch eine Variable sein.

Problem ist nur du kannst nicht:

int** a;
a = new int[x][y]; machen.

Ich hab das mal so gelöst gehabt, aber ka mehr ob das ging^^:

int *a;
a = new int[x];
for(int i=0;i<x;i++)
{
a[i] = new int[y];
}

Kannst ja mal probieren.

//zwar geht:
int** mix_matrix = new int*[vector_dimension];
//das geht aber nicht:
for( unsigned int matrix_column = 0 ; matrix_column < patches->size() ; matrix_column++ ) 
      mix_matrix[matrix_column] = new int[gewuenschte_groesse];

PatchGenerator.cpp:21: error: name lookup of ‘matrix_column’ changed for new ISO ‘for’ scoping

int** PatchGenerator::transform_patches_to_vectors_and_merge_to_matrix( vector<QImage*>* patches , int rect_size ) {
    int vector_dimension = rect_size * rect_size;
    int number_of_patches = patches->size();
    int** mix_matrix = new int*[number_of_patches];

    for( unsigned int matrix_column = 0 ; matrix_column < patches->size() ; matrix_column++ ) {
        int* vector = new int[vector_dimension];
        for( int x = 0 ; x < rect_size ; ++x ) 
            for( int y = 0 ; y < rect_size ; ++y ) 
                vector[ x * rect_size + y ] = patches->at( matrix_column )->pixel( x , y );
        mix_matrix[ matrix_column ] = vector;
    }
    return mix_matrix;
}