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Get value points from a wave for every x in a vector

milind0y

Hi,

        I have 2 waveforms. First I find the intersection of the 1st wave to some threshold to get a list of time points where it crosses like:

drGetWaveformXVec(cross(clip(VT("/IN") 199u 220u ) VAR("vdd")/2 1 "rising" t "time" ))

now from these time points vector I want to get a vector of all the y points of the 2nd waveform at the corresponding time points. Something like:

value(VT("/wave2") drGetWaveformXVec(cross(clip(VT("/IN") 199u 220u ) VAR("vdd")/2 1 "rising" t "time" )))

and then find the max and min of all the values. Value function as I wrote above does not work. How can I accomplish this?

Thanks,

Milind

  • Dear milind0y,

    I do not think the value() function argument "g_value" works with a waveform. From the ocean reference manual:

    "Value (X value) at which to provide the Y value. If a string has
    been defined for a value or set of values, the string may be used
    instead of the value."

    How about the following? I am sure others can provide a more efficient solution, but I have used code similar to this.

    zcross_wave1 = cross(wave1 0 0 "rising" t "cycle")

    xvector = drGetWaveformXVec(zcross_wave1)

    xvector_length = drVectorLength(xvector)

    declare(y_values[xvector_length])

    ERR_VAL = 9e99

    min_y_value = 0.0 + ERR_VAL

    max_y_value = 0.0 - ERR_VAL

    for( i 1 xvector_length

    y_values[i] = value(wave1 zcross_wave1[i])

    min_y_value = if(y_value[i] < min_y_value y_value[i] min_y_value)
    max_y_value = if(y_value[i] > max_y_value y_value[i] max_y_value)

    )

    Shawn

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