pyhctsa.operations.medical.pol_var¶

pyhctsa.operations.medical.pol_var(x, d=1, D=6)¶

Compute the POLVARd measure of a time series.

The POLVARd (also called Plvar) measure quantifies the probability of obtaining a sequence of consecutive ones or zeros in a symbolic sequence derived from the input time series.

This measure was originally introduced in [1].

The original implementation applied this measure to RR interval sequences (typically in milliseconds), with the symbolic threshold d representing raw amplitude differences. This implementation generalizes it to z-scored time series, such that d is specified in units of standard deviation.

The function is derived from the MATLAB implementation by Max A. Little (2009) and Ben D. Fulcher.

References

Parameters:¶

x : array-like¶

The input time series.

d : float¶

Symbolic coding threshold in units of standard deviation.

D : int¶

Word length for detecting consecutive sequences (commonly D=6).

Returns:¶

The probability of obtaining a sequence of D consecutive ones or zeros.

Return type:¶

float