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Re: ODE where y' = f(t,y0,...,yn)
Posted:
Jul 23, 2007 4:13 AM


Thanks for your answer but I've got Matlab R12.1 only and I can't find these functions on my version. Is it normal ? What can I do ?
"Steven Lord" <slord@mathworks.com> wrote in message <f7o7lp$8pr$1@fred.mathworks.com>... > > "redcic" <cedric.louyot@gmail.com> wrote in message > news:1184861292.880614.114670@w3g2000hsg.googlegroups.com... > > Hi all, > > > > I'm currently trying to solve an ODE that looks like this : > > y' = f(t,y0,...,yn) > > > > where yi is the state vector taken at step i. > > This is not an ODE. This is a delaydifferential equation. > > > This requires more explanation: I want ode45 to compute the state > > vector y at times that I choose (like I can do using tspan). However I > > need to use the state vector y computed at all the previous time steps > > I've choosen in order to calculate y' at the current time step. > > > > Is there any way I do that using ode45 ? > > Use the delaydifferential equation solvers DDE23 or DDESD instead. > > http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/dde23.html > http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/ddesd.html > >  > Steve Lord > slord@mathworks.com > >



