Monte Carlo help

[James]

Greetings,

I am running into some trouble running a Monte Carlo simulation. In my
ADE window I have an expression like:
Itot=I1+I2
which depends on expressions I1 and I2:
I1=IT("/n1/D")
I2=IT("/n2/D")
When running a single simulation from the ADE, everything works great.

When I set up a Monte Carlo, the simulations run but I get the
following message (or similar, I am away from my workstation right
now
Error evaluating expression xxx

Saving the script, the monteCarlo.ocn file contains lines like:

monteExpr("I1" "(I1=(IT(\"/n1/D\")")))

etc.

It seems like ocean doesn't like these. So my question is, how do I
create a monteExpr that depends on other expressions? The example I
have here is simple and I can put everything in one expressions but my
real problem requires a humongous expression, so this isn't an option.

Any help will be appreciated.

 

[Andrew Beckett]

On Wed, 30 Nov 2005 18:44:12 -0600, James <no_spam@please.com> wrote:

Greetings,

I am running into some trouble running a Monte Carlo simulation. In my
ADE window I have an expression like:
Itot=I1+I2
which depends on expressions I1 and I2:
I1=IT("/n1/D")
I2=IT("/n2/D")
When running a single simulation from the ADE, everything works great.

When I set up a Monte Carlo, the simulations run but I get the
following message (or similar, I am away from my workstation right
now
Error evaluating expression xxx

Saving the script, the monteCarlo.ocn file contains lines like:

monteExpr("I1" "(I1=(IT(\"/n1/D\")")))

etc.

It seems like ocean doesn't like these. So my question is, how do I
create a monteExpr that depends on other expressions? The example I
have here is simple and I can put everything in one expressions but my
real problem requires a humongous expression, so this isn't an option.

Any help will be appreciated.

Two things:

1. Use i("/n1/D" ?result 'tran) instead of IT(). You should really stick to
OCEAN functions with monte carlo rather than using Artist functions (yes, I know
they _ought_ to work - but in some cases they don't. There's a PCR to make the
older Artist calculator functions like IT, VT, IF, VF etc use OCEAN underneath).
2. These are going to produce waveform data - so I suspect you have specified
them as producing scalar output by mistake. Anything that ends up in the export
statements in the netlist needs to produce a scalar expression - so that it can
record the single value and then produce histogram type information afterwards.
If you want to capture entire waveforms, then you'd need to ask it to "save
family data between runs", and then plot the expressions afterwards.
Only scalar expressions should end up as monteExpr() in OCEAN.

Regards,

Andrew.