cleanup_timestamps removes zero time value if minimum is set to zero

[muendlein]

Python version

Python 3.7 Asammdf 7.07

Code

MDF version

4.1

Code snippet

from asammdf import MDF, Signal
import numpy as np

timestamps = np.array([0,1,2,3,4])
data = np.random.rand(5)

mdf = MDF()
sig = Signal(name="test",timestamps=timestamps, samples=data)
mdf.append(sig)

mdf_cleaned = mdf.cleanup_timestamps(0, 10)

print(mdf_cleaned.select(["test"])) 

"""
[<Signal test:
	samples=[0.93248571 0.30446711 0.26117341 0.31794446]
	timestamps=[1. 2. 3. 4.]
	invalidation_bits=None
	unit=""
	conversion=None
	source=None
	comment=""
	mastermeta="('time', 1)"
	raw=False
	display_names={}
	attachment=None>
]
"""

Description

As shown in the example timestamps that start with zero will be removed if cleanup_timestamps(0, ...) is called. From doing minimal debugging it seem like that >= minimum is called which should not remove the zero. However the log call to get the exponent obviously does not work with zero which may be the culprit here. Using any non zero start value works as expected.

[danielhrisca]

@muendlein please try the development branch code