Mercurial > repos > public > sbplib

annotate +time/+rk4/rungekutta_4.m @ 352:9b3d7fc61a36 feature/hypsyst

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Changed operator in Utux
author Ylva Rydin <ylva.rydin@telia.com>
date Thu, 10 Nov 2016 20:47:40 +0100
parents 48b6fb693025
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
1 % Takes one time step of size k using the rungekutta method
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
2 % starting from v_0 and where the function F(v,t) gives the
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
3 % time derivatives.
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
4 function v = rungekutta_4(v, t , k, F)
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
5 k1 = F(v ,t );
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
6 k2 = F(v+0.5*k*k1,t+0.5*k);
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
7 k3 = F(v+0.5*k*k2,t+0.5*k);
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
8 k4 = F(v+ k*k3,t+ k);
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
9 v = v + (1/6)*(k1+2*(k2+k3)+k4)*k;
48b6fb693025 Initial commit.
Jonatan Werpers <jonatan@werpers.com>
parents:
diff changeset
10 end