Opened 9 years ago

Closed 9 years ago

Last modified 9 years ago

#3500 closed defect (fixed)

Incorrect numerical output not detected

Reported by: dma@… Owned by: Willi Braun
Priority: critical Milestone: 1.9.4
Component: Run-time Version:
Keywords: solver error, state selection Cc:

Description

When the stop time of the attached simulation is increased from 2 to 100, a clearly incorrect result is produced but no error indication is given. When the number of output intervals is increased from 500 to 5000 the correct result is given.

It seems that the solver (dassl) uses the stop time and number of intervals for a first guess at step size. With num. of intervals at 500 the step size is much too large, but its error estimator does not properly catch the error.

Attachments (1)

InconsistentNumericalResults.zip (43.6 KB ) - added by dma@… 9 years ago.
Modelica source file and plot of results

Download all attachments as: .zip

Change History (7)

by dma@…, 9 years ago

Modelica source file and plot of results

comment:1 by Lennart Ochel, 9 years ago

Component: UnknownRun-time
Owner: changed from somebody to Willi Braun
Status: newassigned

comment:2 by Willi Braun, 9 years ago

Keywords: state selection added
Priority: highcritical
Status: assignedaccepted

Currently, we check the state selection to switch states just at output points and that's the reason the simulation throws wrong results here.

comment:3 by Willi Braun, 9 years ago

Resolution: fixed
Status: acceptedclosed

This is fixed by 212791 where the way how starting values are calculated for the non-linear system have been changed.

comment:4 by Dietmar Winkler, 9 years ago

Milestone: Future1.9.4

comment:5 by Martin Sjölund, 9 years ago

Milestone: 1.9.41.9.4-1.9.x

Milestone renamed

comment:6 by Martin Sjölund, 9 years ago

Milestone: 1.9.4-1.9.x1.9.4

Milestone renamed

Note: See TracTickets for help on using tickets.