Rising

Calculate the rising edge of a waveform. Errors if image or scalar provided.

First, applies smoothing by taking weighted nearest and next-nearest neighbour contributions to y values whose difference from their neighbours is more than 0.2 times the total range in y. The global maximum y value is then identified along with the first x position to the left of the peak where the y value is less than or equal to half the global maximum. If all values of y to the left of the peak are greater than half the global maximum, the position of the global maximum is used. The value of x at this position is returned.

Source code in builtins/rising.py
@staticmethod
def evaluate(waveform: WaveformVariable) -> float:
    """
    Calculate the rising edge of a waveform. Errors if image or scalar provided.

    First, applies smoothing by taking weighted nearest and next-nearest
    neighbour contributions to  y values whose difference from their neighbours
    is more than 0.2 times the total range in y. The global maximum y value is then
    identified along with the first x position to the left of the peak where the y
    value is less than or equal to half the global maximum. If all values of y to
    the left of the peak are greater than half the global maximum, the position of
    the global maximum is used. The value of x at this position is returned.
    """
    half_max_left, _ = Builtin.calculate_fwhm(waveform)
    return half_max_left