If I have a list
list={3,7,4,5,1}
how to get the List of Intervals /Ranges
result = {{1,3},{3,4},{4,5},{5,7}}
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asked Jan 21, 2012 at 9:22
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2 Answers
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Maybe
Partition[Sort@list, 2, 1]
giving
{{1, 3}, {3, 4}, {4, 5}, {5, 7}}
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$\begingroup$ Beat me to it - 7 secs! Deleting mine, and +1. $\endgroup$ Jan 21, 2012 at 9:30
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Tom's answer is canonical, but you could also use:
With[{s = Sort[list]}, Transpose[{Most[s], Rest[s]}]]
which seems to be marginally faster for large lists. (In which case most of the time is spent sorting.)
answered Jan 22, 2012 at 3:55
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2$\begingroup$ Alternatively:
Composition[Transpose, Through, {Most, Rest}, Sort][list]. $\endgroup$ Jan 22, 2012 at 4:26