minimumIntervalLength in tgio.save not not working as expected

[timsainb]

I am saving textgrids of syllables of birdsong and noticed the tg.save function does not work as expected.

The save function

def save(self, fn, minimumIntervalLength=MIN_INTERVAL_LENGTH):

    for tier in self.tierDict.values():
        tier.sort()

    # Fill in the blank spaces for interval tiers
    for name in self.tierNameList:
        tier = self.tierDict[name]
        if isinstance(tier, IntervalTier):

            tier = _fillInBlanks(tier,
                                 "",
                                 self.minTimestamp,
                                 self.maxTimestamp)
            if minimumIntervalLength is not None:
                tier = _removeUltrashortIntervals(tier,
                                                  minimumIntervalLength)
            self.tierDict[name] = tier

    for tier in self.tierDict.values():
        tier.sort()

    # Header
    outputTxt = ""
    outputTxt += 'File type = "ooTextFile short"\n'
    outputTxt += 'Object class = "TextGrid"\n\n'
    outputTxt += "%s\n%s\n" % (repr(self.minTimestamp),
                               repr(self.maxTimestamp))
    outputTxt += "<exists>\n%d\n" % len(self.tierNameList)

    for tierName in self.tierNameList:
        outputTxt += self.tierDict[tierName].getAsText()

    with io.open(fn, "w", encoding="utf-8") as fd:
        fd.write(outputTxt)

takes as input to minimumIntervalLength by default a hardcoded parameter MIN_INTERVAL_LENGTH = 0.00000001.

When segments are longer than that number, it would be expected that they would be left as is. However, with my song, when I do not set that flag, the first syllable in each of my textgrids is changed from: Interval(start=0.339, end=0.387, label='syll') to: Interval(start=0.0, end=0.387, label='syll') Despite the segment length being longer than MIN_INTERVAL_LENGTH. Setting minimumIntervalLength to None fixes the problem in my case, but it looks like something is not working as intended in this function.

Thanks for an excellent toolset! Tim

[timmahrt]

Hello Tim, I'm sorry for the bug. I have fixed the problem and added tests. If you update to 3.7.1, _removeUltrashortIntervals should work correctly with your data.

Of course, if short intervals are not a problem for you, you can also leave it at null and bypass the check.

I found that the function _removeUltrashortIntervals ignores the minTimestamp of a Textgrid. If the Textgrid's minTimestamp was 0, the code should have worked ok, but if the Textgrid's minTimestamp was non-zero, the behaviour would be as you described.

If you find any other bugs or would like to see any other features, please let me know. Thanks! Tim

[timsainb]

Thanks!