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Calculator custom function, SKILL script - output is not plotting

JDUAD

Hello,

My custom SKILL function is not properly working and I can't figure why the output vector is not plotting. Is somebody have some experience writting SKILL scirpt for calculator custom function ?

my code:

"

procedure(average_freq_on_periodic_sample(wave start stop period)

  cond(

    (drIsWaveform(wave)

      let((xVec yVec len lastXVal outXVec outYVec start_sample stop_sample sample outWave)

        xVec=drGetWaveformXVec(wave)
        yVec=drGetWaveformYVec(wave)
        len=drVectorLength(xVec)
        lastXVal=drGetElem(xVec len-1)
       

        outXVec= nil  
        outYVec= nil  
                     

        sample = 0

        for(i 0 (round lastXVal/period)-1
          start_sample = sample + start
          stop_sample = sample + stop
          outYVec = append( outYVec list(average(clip(VT("/clkout") start_sample stop_sample ))))
          outXVec = append( outXVec list(sample))
          sample = sample + period

          printf("%f \n", average(clip(VT("/clkout") start_sample stop_sample ) ))
      
        )
    printf("final ylist %L \n", outYVec)
  ;
      ;--------------------------------------------------------
      ; Construct final waveform, set expression and return
      ;--------------------------------------------------------
      outWave=drCreateWaveform(drCreateVec('double outXVec) drCreateVec('double outYVec))
      famSetExpr(outWave 'average_freq_on_periodic_sample(,famGetExpr(wave) ,start ,stop ,period))
      outWave

      )
    )

    (famIsFamily(wave)

      famMap('average_freq_on_periodic_sample wave start stop period)

    )

    (t

      error("myFunction cannot handle argument %L\n" wave)

    )
  )
)

"

Thanks!

  • The first thing I saw was that inside the loop it's doing VT("/clkout")

              outYVec = append( outYVec list(average(clip(VT("/clkout") start_sample stop_sample ))))

    That would be rather odd for a calculator function to reference a fixed signal. My assumption is that you should be using wave at this point (it's also in the printf shortly afterwards). If I change it to wave then the function works (it's a bit slow though).

    It appears to be computing a periodic average, so maybe you can use this instead: Periodic Average function for ViVA calculator (written by me)?

    Andrew

  • in reply to Andrew Beckett

    Thank you Andrew, your correction solves my problem.

    This function's purpose is to perform periodic frequency average using frequency(clip(wave start_sample stop_sample) rather than the average(clip (wave start_sample stop_sample). However,  the output plot does not correspond to the calculus performed inside the function (different from print output). Do you have any clues on this issue?

    Regards,
    JDU

  • in reply to JDUAD

    I don't understand. Your code uses average (I thought that was a bit odd, since that doesn't chime with the function name) and the points produced in the waveform do match the information printed out within (I checked with an example).

    I can only assume that you've updated the code and something else is wrong? If so, please post the updated code, as guessing what might be wrong is rather difficult. Maybe you could also illustrate it with an example showing the problem?

    Andrew

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