[MBDyn-users] make restart file

masarati at aero.polimi.it masarati at aero.polimi.it
Sun Jun 27 20:37:43 CEST 2010

> The manual includes 'make restart file' as a 'control data' option.
> However, this option seems to generate an incomplete restart file.  Is
> restart a working feature, or available in some form for testing?

It is an incomplete, experimental and essentially abandoned feature.  It
generates an incomplete restart file that is supposed to represent the
model in its running state, and needs some manual intervention to
determine what to do to continue the analysis from that point on.  Since
it is essentially abandoned, recently developed features do not support
it; they basically generate a comment like

# <feature> not implemented yet

so you need to manually replace them with actual input as needed.

Implementing a thorough restart would require significant effort, since it
either needs to:

a) implement a binary input format that basically reconstructs the
internal state of the model database

b) enhance the current textual input format to allow to read in internal
states that are not currently read (nor saved)

In both cases, it's a lot of work that doesn't pay off.

Case (b), which is in the spirit of the initial implementation, would be
more useful, in my opinion, because the textual format would allow to
modify the model before restarting.  In fact, in my opinion, the most
useful scenario for restart would be to generate a reference solution to
be used as starting point for other solutions with perturbations in the
model (mainly loads, but also configuration and so).  If you generate a
binary format, modifying the model would be nearly impossible.

Cheers, p.

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