2008/1/22, Anders Logg <[EMAIL PROTECTED]>: > On Tue, Jan 22, 2008 at 03:05:45PM +0100, Anne Voigt wrote: > > Thank you for the fast answer. > > > > Am Dienstag, den 22.01.2008, 11:38 +0100 schrieb Anders Logg: > > > On Tue, Jan 22, 2008 at 11:09:27AM +0100, Anne Voigt wrote: > > > > > > > > Thank you. I now try to write my own Tensor by deriving from the > > > > GenericTensor class. Could you write me some information about the > > > > interface? > > > > Especially what the parameters of the function > > > > GenericTensor::get(..) and GenericTensor::set(..) are? It is not clear > > > > for me and I cannot find a documentation about it. > > > > > > > > Regards, > > > > Anne > > > > > > virtual void set(const real* block, > > > const uint* num_rows, > > > const uint* const * rows) = 0; > > > > > > block is an array with values to be set > > > > > > num_rows is an array of length rank() > > > > > > num_rows[i] is the number of "rows" to be set for axis i > > > > > > rows[i] is an array with the "rows" to be set for axis i > > > > > > the length of the array block is num_rows[0]*num_rows[1]*... > > > > > > For a matrix (rank = 2), the values will be set according to > > > > > > for (int i = 0; i < num_rows[0]; ++i) > > > for (int j = 0; j < num_rows[1]; ++j) > > > A[rows[i], rows[j]] = block[i*num_rows[1] + j]; > > > > When I understood it correctly, the last line should be: > > > > A[rows[0][i], rows[1][j]] = block[i*num_rows[1] + j]; > > > > Is this correct or did I a mistake? > > Correct, my mistake.
Of course, you didn't literally mean to write "A[i,j]" in C++, which won't do what it looks like, and can be difficult to debug, since it actually compiles. The binary operator "," evaluates to one (the first?) of the values. -- Martin _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
