[ojAlgo-user] BasicMatrix get method is slow

[Stathis M. <sta...@gm...>]

Hi,
I am trying to create a Tensor API using Ojalgo as backend.
Actually a 3D Tensor is an Arraylist of BasicMatrix objects.
To get  element i,j,k from a tensor, I actually getting the i,j entry from
the k-th oject on the arraylist.
If i try to loop through all elements of these BasicMatrix object, the time
i need is noticeable more or using Java double[][] arrays.
E.g. accessing all element(using a triple-loop) of a 2000x20000x10 (10
BasicMatrix objects of dimension 2000x20000), i need hours(!!!!) of
waiting, while will Java double[][] i need seconds...
(This is the arraylist i got:
 ArrayList<BasicMatrix> tensor;
and this is how to get the items:
Y.get(U_i, P_i, C_i).doubleValue();
)

Is this behavior normal? Am I doing something wrong?
Thanks in advance.
Stathis