#!/usr/bin/env python
# coding: utf-8

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get_ipython().run_line_magic('pylab', 'inline')
from pyannote.core import notebook


# # Segment (`pyannote.core.segment.Segment`)

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from pyannote.core import Segment


# **`Segment`** instances are used to describe temporal fragments (e.g. of an audio file).

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# start time in seconds
s = 1.
# end time in seconds
e = 9.
segment = Segment(start=s, end=e)
segment


# **`Segment`** instances are nothing more than 2-tuples augmented with several useful methods and properties.

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start, end = segment
print('from {} to {}'.format(start, end))


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print('Segment %s ends at %g seconds.' % (segment, segment.end))
print('Its duration is %g seconds.' % (segment.duration))
print('Its middle stands as %g seconds.' % (segment.middle))


# ### Intersection

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other_segment = Segment(4, 13)
if segment.intersects(other_segment):
    print('Segment %s intersects other segment %s.' % (segment, other_segment))
    intersection = segment & other_segment
    print('Their intersection is %s.' % (str(intersection)))


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notebook.crop = Segment(0, 15)
segment


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other_segment


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segment & other_segment


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other_segment = Segment(13, 20)
if not (segment & other_segment):
    print('Those two segments do not intersect.')


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notebook.crop = Segment(0, 30)
segment


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other_segment


# ### Inclusion

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other_segment = Segment(5, 6)
if other_segment in segment:
    print('%s in included in %s' % (other_segment, segment))


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t = 23.
if not segment.overlaps(t):
    print('%s does not contain time %f' % (segment, t))


# ### Other operations

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other_segment = Segment(10, 30)
print('Union of %s and %s is %s' % (segment, other_segment, segment | other_segment))


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other_segment = Segment(14, 15)
print('Gap between %s and %s is %s' % (segment, other_segment, segment ^ other_segment))


# # SlidingWindow (`pyannote.core.segment.SlidingWindow`)

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from pyannote.core import SlidingWindow, Timeline


# ### Iteration

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notebook.crop = Segment(0, 10)
window = SlidingWindow(start=0.0, step=1.1, duration=2., end=10.)
Timeline(window)


# ### Cropping

# Given an interval, `.crop` can be used to return every position of the sliding window within this interval. 

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interval = Segment(3., 7.5)
interval


# `strict` mode only returns fully contained positions.

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indices = window.crop(interval, mode='strict')
Timeline(window[i] for i in indices)


# `loose` mode returns any intersecting position.

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indices = window.crop(interval, mode='loose')
Timeline(window[i] for i in indices)


# `center` mode centers first and last position on interval boundaries.

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indices = window.crop(interval, mode='center')
Timeline(window[i] for i in indices)


# ### Need help?

# You can always try the following...  
# Who knows? It might give you the information you are looking for!

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help(Segment)