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drIsWaveform Function

Driss

Hello,

I am trying to find out if the evaluation of a expression is a waveform or a scalar type.

For example:

  myExpression = "dB20(VF(\"/sig_out\"))"

  eval = car(errsetstring(myExpression))

I would like to have a function that returns t or nil depending on whether eval is a waveform or a scalar. 

I read from the following post, that the drIsWaveform should do exactly what I want:

  www.designers-guide.org/.../YaBB.pl



However unlike in this post, the evaluation of my expression returns: srrWave: =XXX instead drwave=XXX

so that  drIsWavefirm(eval) returns the wrong value (nil in this case)

My question:

1) Why do I get a srrWaveform instead of a drWaveform?

2) What is the difference between both types?

3) is there any documentation related to the different data structures used in ADE? 

Many Thanks for your help.

Driss

  • Andrew Beckett
    Cedric, waveform objects simply changed between IC5141 and IC61X from drWave to srrWave. This is just an internal representation detail that there's no need to worry about. The same APIs work, including the one you mention- drIsWaveform. This only tells you if it is a simple waveform - you'd need to call famIsFamily to check if it is a family waveform. So maybe that is the reason why it is returning nil? Regards, Andrew
  • Driss
    Dear Andrew,
    Thank you very much for the quick answer. Indeed the expression was "stored" in a waveform Family and using famIsFamily solved my problem.

    I still face now another issue with the evaluation of user expressions combinations.
    For example these 3 expressions are evaluable with the calculator:
    myExpr1 = "db20(VF(\ "sig_out\ "))"
    myExpr2 = "db20(VF(\ "sig_in\ "))"
    myExpr3 = "myExpr1 / myExpr2"

    Still opening the psf directory with openResults(psf_dir_path), neither evalstring() or errsetstring() function works in the third case.
    Is there a simple way to evaluate expression combination as the calculator does? Would you have any suggestion?
    Thanks again for your help.
    Best Regards
  • ebecheto
    why do you put quote ?
    myExpr1 = db20(VF("sig_out"))
    myExpr2 = db20(VF("sig_in"))
    myExpr3 = myExpr1 / myExpr2

    should work
  • Driss
    my purpose is to import some user defined expressions stored in a csv file and apply each of them to the current open simulation results.
    Reading the csv file I get all my expressions in a string format (this is why I have quotes)

    Errsetstring() has worked so far perfectly for the evaluation of expressions containing signal names, But the combination of expressions doesn´t work as I mentioned before.
    One approach I have in mind would be to import each of the expression in a container structure that holds name and string value of each expression
    Something like: ExprStruct( ("myExpr1" "db20(VF("sig_out"))" )
    ( "myExpr2" "db20(VF("sig_in"))" ) )
    ( "myExpr3" "myExpr1/myExpr2" ) )
    )

    One´s should then parse non-evaluable strings values into substrings and try to evaluate each of them....

    This seems however to be a bit heavy and tedious and I am wondering if there is a simpler way to do it as the calculator already manage to evaluate expression combinations.
    Maybe by invoking the calculator through skill code?
    Thanks again for sharing your experience.
  • Andrew Beckett

    You'll need to ensure that the SKILL variables myExpr1 and myExpr2 get set so that the resulting expression gets evaluated properly. You could do that with the set() function - so something like set(concat(exprName) car(errsetstring(expression))) . This will create global variables called myExpr1, myExpr2 etc - you might then want to construct a let() with all the variables you are creating and then evaluate them all within that let so that they all get created as local - but I'll leave that as an exercise for you...

    Regards,

    Andrew.

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