[R-sig-dyn-mod] lag value stability

[Tom Drake]

Dear R-sig / Thomas Petzoldt

Many thanks for your previous response about rootSolve and simecol, this was very useful.

I’m experiencing some stability issues with lagvalue. I have model variants that have worked without problems for some time that have recently begun to throw errors below.

Error in deSolve::lagvalue(tlag) :
  pastvalue can only be called from 'func' or 'res' when triggered by appropriate integrator.

OR

Error in deSolve::lagvalue(tlag) :
  illegal input in lagvalue - lag, 406.235, too large, at time = 415.235

Sometimes it will work and sometimes it won’t, I cannot work out what is causing the problems. I have tried using “deSolve::lagvalue” to avoid conflicts with other packages but still the same.

Any suggestions on what has caused these problems suddenly appear and how to address them are welcome.

Best wishes

Tom



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