Error when calling and evaluating skill function in ADE-L Parametric Analysis and in ADE-XL

Dear all,

I've got a problem to which I couldn't find answer.

I've made a customized skill function to do calculation and evaluation after PSS analysis. It takes in time domain waves from PSS and returns a number. I create a new output parameter  in the output window of my ADE-L which calls this function, it works fine and returns the number. 

However, when I run Parametric Analysis in ADE-L, or run it in ADE-XL, evaluation fails and I get the following error. 

ERROR (ADE-1057): Could not evaluate expression

        Name:'MyFunction'

        Expression:'MyFunction((v("/OUTP" ?result "pss_td") - v("/VSS" ?result "pss_td")) (VOUT_H / 2) )'

     because of the following error(s)

        ("ilGetNumber" 0 t nil ("*Error* ilGetNumber: arg must be a number" srrWave:0x2aacaa20))

     Ensure that the definition of the expression is correct.

*Error* ("ilGetNumber" 0 t nil ("*Error* ilGetNumber: arg must be a number" srrWave:0x2aacb060))

 The skill functions I call in my function are following:

cross()

drGetWaveformXVec()  drGetWaveformYVec()

drVectorLength()

drCreateVec()

drGetElem()

drSetElem()

drCreateWaveform()

ymax()  ymin() 

There isn't any ilGetNumber() function in my code. Very weird.

I guess that in order to call a skill function in Parametric Analysis or in ADE-XL, I need to change something in my code. But I couldn't find any information. Could anybody help me on this? Many thanks!

Best Regards,

Mingxu