Equation to compute the psi dissimilarity score
(Birks and Gordon 1985). Psi is computed as \(\psi = (2a / b) - 1\),
where \(a\) is the sum of distances between the relevant samples of two
time series, and \(b\) is the cumulative sum of distances between
consecutive samples in the two time series.
If a is computed with dynamic time warping, and diagonals are used in the
computation of the least cost path, then one is added to the result of the equation above.
Arguments
- a
(required, numeric) output of
cost_path_sum_cpp()on a least cost path.- b
(required, numeric) auto sum of both sequences, result of
auto_sum_cpp().- diagonal
(optional, logical). Must be TRUE when diagonals are used in dynamic time warping and for lock-step distances. Default: FALSE.
See also
Other Rcpp_dissimilarity_analysis:
null_psi_dynamic_time_warping_cpp(),
null_psi_lock_step_cpp(),
psi_dynamic_time_warping_cpp(),
psi_lock_step_cpp()