Mercurial > repos > public > sbplib
annotate +time/+expint/Magnus_mp.m @ 511:57f3493f851b feature/quantumTriangles
Added sqrt of Ji in the right places, not sure about the interfaces, will not test it properly now
author | Ylva Rydin <ylva.rydin@telia.com> |
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date | Thu, 08 Jun 2017 10:33:36 +0200 |
parents | 566304a5733e |
children | 4ef2d2a493f1 |
rev | line source |
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505
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
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1 % Takes one time step of size k using the magnus midpoinr |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
2 % starting from v_0 and where the function F(v,t) gives the |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
3 % time derivatives. |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
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4 function v = Magnus_mp(v,D, t , k) |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
5 |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
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6 if isa(D,'function_handle') |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
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7 % v = krylov(k*D(t +k/2*t),v); |
509
566304a5733e
changed the magnus midpoint rule
Ylva Rydin <ylva.rydin@telia.com>
parents:
505
diff
changeset
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8 v = expm(k*D(t +k/2))*v; |
505
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
9 else |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
10 %v = krylov(k*D,v); |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
11 v = expm(k*D)*v; |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
12 end |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
13 |
49bc2929dfb1
Added the midpont magnus exponential integrator
Ylva Rydin <ylva.rydin@telia.com>
parents:
diff
changeset
|
14 end |