how to pass population present in cell to ga() function??...

I need to generate a 3D population matrix i.e. the first entry of population matrix is a 3x4 cell and similarly the 2nd entry.......I need to perform the all operations i.e.fitness scaling,selection function crossover, mutation, migration interval etc. on this type of matrix which has 20 rows and each row is a 3x4 cell.....