Warning

This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.

is_pseudographical

is_pseudographical(sequence)

Returns True if some pseudograph can realize the sequence.

Every nonnegative integer sequence with an even sum is pseudographical (see [1]).

Parameters:sequence (list or iterable container) – A sequence of integer node degrees Returns:valid – True if the sequence is a pseudographic degree sequence and False if not. Return type:bool

Notes

The worst-case run time is O(n) where n is the length of the sequence.

References

[1]	F. Boesch and F. Harary. “Line removal algorithms for graphs and their degree lists”, IEEE Trans. Circuits and Systems, CAS-23(12), pp. 778-782 (1976).