find_const_seq_long

mdtools.numpy_helper_functions.find_const_seq_long(x, tol=1e-08, sort=False)[source]

Find the longest sequence of constant values in an array.

If there exist multiple sequences with the longest length, the first of them is returned.

Parameters:

x (array_like) – 1-dimensional array in which to find the longest sequence of constant values.
tol (scalar, optional) – Tolerance value within which consecutive elements of x are considered to be equal.
sort (bool, optional) – If True, sort x before searching for sequences of constant values.

Returns:

start_ix (int) – Index indicating the start of the longest sequence of constant values in x.
length (int) – The actual length of this sequence.
val (scalar) – The value of this sequence. Because consecutive values can differ by tol, this is the mean value of the sequence.

See also

get_const_seqs(): Get all sequences of constant values in an array.
find_const_seq_n(): Find the first sequence of at least n constant values in an array

Examples

>>> a = np.array([0, 4, 4, 4, 2, 2])
>>> mdt.nph.find_const_seq_long(a)
(1, 3, 4.0)
>>> mdt.nph.find_const_seq_long(a, sort=True)
(3, 3, 4.0)
>>> np.sort(a)
array([0, 2, 2, 4, 4, 4])

Edge cases:

>>> a = np.array([])
>>> mdt.nph.find_const_seq_long(a, sort=True)
(array([], dtype=int64), 0, array([], dtype=float64))
>>> a = np.ones(3)
>>> mdt.nph.find_const_seq_long(a, sort=True)
(0, 3, 1.0)