Hi, The matrix_exponential() and square_matrix_power() functions are the problem. If an equivalent for an array of matrices could be designed, it could be added as a new function to lib.linear_algebra.matrix_exponential and lib.linear_algebra.matrix_power. This is a difficult problem.
Regards, Edward On 19 May 2014 10:46, Troels E. Linnet <[email protected]> wrote: > Follow-up Comment #18, task #7793 (project relax): > > It remains still to figure out how to speed up the numerical models: > > The problem is how to make a 3 dimensional array, which is a list which > contains matrices. > > Each matrix is multiplied with for example a constant tcp. > > ############ > # Loop over the time points, back calculating the R2eff values. > for i in range(num_points): > # This matrix is a propagator that will evolve the magnetization with the > matrix R for a delay tcp. > eR_tcp = matrix_exponential(R*tcp[i]) > > # This is the propagator for an element of [delay tcp; 180 deg pulse; 2 > times delay tcp; 180 deg pulse; delay tau], i.e. for 2 times tau-180-tau. > prop_2 = dot(dot(eR_tcp, matrix_exponential(cR2*tcp[i])), eR_tcp) > > # Now create the total propagator that will evolve the magnetization under > the CPMG train, i.e. it applies the above tau-180-tau-tau-180-tau so many > times as required for the CPMG frequency under consideration. > prop_total = square_matrix_power(prop_2, power[i]) > > # Now we apply the above propagator to the initial magnetization vector - > resulting in the magnetization that remains after the full CPMG pulse train. > It is called M of t (t is the time after the CPMG train). > Moft = dot(prop_total, M0) > > ########## > > _______________________________________________________ > > Reply to this item at: > > <http://gna.org/task/?7793> > > _______________________________________________ > Message sent via/by Gna! > http://gna.org/ > > > _______________________________________________ > relax (http://www.nmr-relax.com) > > This is the relax-devel mailing list > [email protected] > > To unsubscribe from this list, get a password > reminder, or change your subscription options, > visit the list information page at > https://mail.gna.org/listinfo/relax-devel _______________________________________________ relax (http://www.nmr-relax.com) This is the relax-devel mailing list [email protected] To unsubscribe from this list, get a password reminder, or change your subscription options, visit the list information page at https://mail.gna.org/listinfo/relax-devel
