annotate +time/+expint/Magnus_mp.m~ @ 696:7c16b5af8d98 feature/quantumTriangles

Add Jonatans symbolic lifehax
author Ylva Rydin <ylva.rydin@telia.com>
date Thu, 05 Oct 2017 18:04:23 +0200
parents bc39bb984d88
children 8434063ed162
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
513
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
1 % Takes one time step of size k using the magnus midpoinr
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
2 % starting from v_0 and where the function F(v,t) gives the
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
3 % time derivatives.
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
4 function v = Magnus_mp(v,D, t , k,matrixexp,tol)
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
5
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
6 if isa(D,'function_handle')
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
7 switch matrixexp
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
8 case 'expm'
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
9 v = expm(k*D(t +k/2))*v;
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
10 case 'Arnol'
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
11 v = time.expint.expm_Arnoldi(-D(t +k/2),v,k,toler,100);
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
12 else
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
13 %v = krylov(k*D,v);
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
14 % v = expm(k*D)*v;
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
15 end
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
16
bc39bb984d88 Added arnoldi krylov subspace approximation
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff changeset
17 end