RiseOperation problem when first input is nan

[andrewjcraig]

rtamt/rtamt/semantics/stl/discrete_time/online/rise_operation.py

Line 3 in fbf415e

class RiseOperation(AbstractOnlineOperation):

class RiseOperation(AbstractOnlineOperation):
    def __init__(self):
        self.prev = -float("inf")

    def reset(self):
        self.__init__()

    def update(self, sample):
        sample_return = min(- self.prev, sample)
        self.prev = sample

        return sample_return

Given a list of inputs, where the first input in the list is nan.
If the STL file, uses the Rise operator.

The initialisation of the RiseOperation begins with self.prev = -float("inf")

If the sample is float("nan"),

then the return sample = min(- self.prev, sample) == float("inf")

The issue is that if the input is nan, presumably, the return of the rise operator should also be nan.