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How to use getData() without hardcoded results path, for a DC sweep?

dontpanic

Hi! I am unable to get getData() to work without hardcoding the results path for sweeps.

For example if I define the following 3 outputs in a simple DC sweep (variable PATH_TO_DEVICE is a string equal to "DUT.MN"):

output1 getData("DUT.MN:gm" ?result "dc")
output2 getData(strcat(VAR("PATH_TO_DEVICE") ":gm") ?result "dc")
output3 getData(strcat(VAR("PATH_TO_DEVICE") ":gm") ?result "dcOpInfo")

then output1 and output3 evaluate / plot  properly, while output2 produces the error attached below.

The error seems to be that VAR("PATH_TO_DEVICE") returns a srrWave object instead of a string for the DC sweep results (the same expression works fine for the dcOpInfo results in output3!)

How can I workaround this problem? Thanks in advance for any help!

Jorge.

--------------------------------------

*Error* ("strcat" 0 t nil ("*Error* strcat: argument #1 should be either a string or a symbol (type template = \"S\")" srrWave:0x7094c0b0))

ERROR (ADE-1057): Could not evaluate expression
        Name:'output2'
        Expression:'getData(strcat(VAR("PATH_TO_DEVICE") ":gm") ?result "dc")'
     because of the following error(s)
        ("strcat" 0 t nil ("*Error* strcat: argument #1 should be either a string or a symbol (type template = \"S\")" srrWave:0x7094c0b0))
     Ensure that the definition of the expression is correct.

Parents
  • dontpanic

    * I meant, "without hardcoding the SIGNAL path" (the results path is not the issue here)

  • Andrew Beckett
    in reply to dontpanic

    Because the variable could (potentially) have different value per sweep point, it becomes a waveform (or family of waveforms, depending on on the depth of sweeps). 

    For output3 this works because the result for each simulation point will be a scalar value. Because of that, it's computed after each individual simulation and at that point the VAR() will be a string and so the expression works OK. For output2 the result at each simulation point is computed (it's OK, because the VAR is a string) and is determined to be a waveform (because it's from the dc sweep itself). Because it's a waveform, nothing is stored and you just get a waveform icon showing. When you try to plot the waveform at the end, it will then access the entire data set and at this point VAR() is returning a waveform - hence the problem.

    The solution is to use the leafMap function around your expression. This magically handles the fact that part of the expression is a waveform/ family:

    leafMap(getData(strcat(VAR("PATH_TO_DEVICE") ":gm") ?result "dc"))

    Andrew

Reply
  • Andrew Beckett
    in reply to dontpanic

    Because the variable could (potentially) have different value per sweep point, it becomes a waveform (or family of waveforms, depending on on the depth of sweeps). 

    For output3 this works because the result for each simulation point will be a scalar value. Because of that, it's computed after each individual simulation and at that point the VAR() will be a string and so the expression works OK. For output2 the result at each simulation point is computed (it's OK, because the VAR is a string) and is determined to be a waveform (because it's from the dc sweep itself). Because it's a waveform, nothing is stored and you just get a waveform icon showing. When you try to plot the waveform at the end, it will then access the entire data set and at this point VAR() is returning a waveform - hence the problem.

    The solution is to use the leafMap function around your expression. This magically handles the fact that part of the expression is a waveform/ family:

    leafMap(getData(strcat(VAR("PATH_TO_DEVICE") ":gm") ?result "dc"))

    Andrew

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