Calculator - check valid expression

Hi,

Is there any way to check whether the expressions copied from the
calculator are valid or not before running an simulation?

I have tried simply using eval() inside errset(), but that would also
fail on simple expressions like db20(VT("/net1")).

The reason for doing this is that I would like to be sure that
expressions are valid before running simulations that takes
hours(since I've created scripts that groups simulations from
different corners and I want this script to create and plot the
waveforms for me automatically)

Best regards,
Svend

 

[Andrew Beckett]

svendbjarne@gmail.com wrote, on 07/21/08 09:20:

Hi,

Is there any way to check whether the expressions copied from the
calculator are valid or not before running an simulation?

I have tried simply using eval() inside errset(), but that would also
fail on simple expressions like db20(VT("/net1")).

The reason for doing this is that I would like to be sure that
expressions are valid before running simulations that takes
hours(since I've created scripts that groups simulations from
different corners and I want this script to create and plot the
waveforms for me automatically)

Best regards,
Svend

If you separate the simulations from the results post-processing, you can
run the simulations first, then quick re-run the post-processing multiple
times as you debug it, without having to re-run any simulations.

That's what I'd do.

Not sure why you would use eval() with errset. It would be sufficient
to do:

errset(db20(VT("/net1")))

however, this just stops it from failing if there was an error - I still think
that separating the sims from the results post-processing is a good idea
if you're uncertain the results post-processing is robust.

Regards,

Andrew.

 

On Jul 24, 3:32 pm, Andrew Beckett <andr...@DcEaLdEeTnEcTe.HcIoSm>
wrote:

svendbja...@gmail.com wrote, on 07/21/08 09:20:



Hi,

Is there any way to check whether the expressions copied from the
calculator are valid or not before running an simulation?

I have tried simply using eval() inside errset(), but that would also
fail on simple expressions like db20(VT("/net1")).

The reason for doing this is that I would like to be sure that
expressions are valid before running simulations that takes
hours(since I've created scripts that groups simulations from
different corners and I want this script to create and plot the
waveforms for me automatically)

Best regards,
Svend

If you separate the simulations from the results post-processing, you can
run the simulations first, then quick re-run the post-processing multiple
times as you debug it, without having to re-run any simulations.

That's what I'd do.

Not sure why you would use eval() with errset. It would be sufficient
to do:

errset(db20(VT("/net1")))

however, this just stops it from failing if there was an error - I still think
that separating the sims from the results post-processing is a good idea
if you're uncertain the results post-processing is robust.

Regards,

Andrew.

Hi,
thanks for the reply.

When fetching the outputs with
asiGetOutputList(asiGetCurrentSession()), then
type(sevOutputStruct@...->expression) evaluates to a list of symbols.
Using eval() on that list gives me the waveform object or the scalar
value of the expression, but fails when using nested expressions with
multiple value() commands since some of them evaluates to nil before
the simulation.

The post-processing is part of a corner simulation program which after
all corners are done simulating on a LSF cluster, groups the scalar
results from each corner and plots them together with all the grouped
waveforms. It also stores all outputs nets/expressions and analysis in
a table written to a file with writeTable() so the user can go back
and view all plots again at a later time from different simulations.
The processing is robust enough

My hope was that there was some way to validate the expressions before
running the simulation, so that the user won't have to manually edit
this table file if he has some syntax errors in his expressions. For
now I think I'll just evaluate the expression after the simulation and
then force the user to re-enter or discard it if it fails before
plotting the results and storing the table for later use

Regards,
Svend