FunctionDynamicTimeWarpingLibrary   "FunctionDynamicTimeWarping" 
"In time series analysis, dynamic time warping (DTW) is an algorithm for 
measuring similarity between two temporal sequences, which may vary in 
speed. For instance, similarities in walking could be detected using DTW, 
even if one person was walking faster than the other, or if there were 
accelerations and decelerations during the course of an observation. 
DTW has been applied to temporal sequences of video, audio, and graphics 
data — indeed, any data that can be turned into a linear sequence can be 
analyzed with DTW. A well-known application has been automatic speech 
recognition, to cope with different speaking speeds. Other applications 
include speaker recognition and online signature recognition. 
It can also be used in partial shape matching applications." 
"Dynamic time warping is used in finance and econometrics to assess the 
quality of the prediction versus real-world data."
~~ wikipedia
reference:
en.wikipedia.org
towardsdatascience.com
github.com
 cost_matrix(a, b, w) 
  Dynamic Time Warping procedure.
  Parameters:
     a : array, data series.
     b : array, data series.
     w : int         , minimum window size.
  Returns: matrix optimum match matrix.
 traceback(M) 
  perform a backtrace on the cost matrix and retrieve optimal paths and cost between arrays.
  Parameters:
     M : matrix, cost matrix.
  Returns: tuple:
array aligned 1st array of indices.
array aligned 2nd array of indices.
float      final cost.
reference:
github.com
 report(a, b, w) 
  report ordered arrays, cost and cost matrix.
  Parameters:
     a : array, data series.
     b : array, data series.
     w : int        , minimum window size.
  Returns: string report.
