Itakura-Saito Autoregressive Extrapolation of Price [Loxx]Itakura-Saito Autoregressive Extrapolation of Price   is an indicator that uses an autoregressive analysis to predict future prices. This is a linear technique that was originally derived or speech analysis algorithms. 
 What is Itakura-Saito Autoregressive Analysis? 
The technique of linear prediction has been available for speech analysis since the late 1960s (Itakura & Saito, 1973a, 1970; Atal & Hanauer, 1971), although the basic principles were established long before this by Wiener (1947). Linear predictive coding, which is also known as autoregressive analysis, is a time-series algorithm that has applications in many fields other than speech analysis (see, e.g., Chatfield, 1989).
Itakura and Saito developed a formulation for linear prediction analysis using a lattice form for the inverse filter. The Itakura–Saito distance (or Itakura–Saito divergence) is a measure of the difference between an original spectrum and an approximation of that spectrum. Although it is not a perceptual measure it is intended to reflect perceptual (dis)similarity. It was proposed by Fumitada Itakura and Shuzo Saito in the 1960s while they were with NTT. The distance is defined as: The Itakura–Saito distance is a Bregman divergence, but is not a true metric since it is not symmetric and it does not fulfil triangle inequality.
read more:  Selected Methods for Improving Synthesis Speech Quality Using Linear Predictive Coding: System Description, Coefficient Smoothing and Streak  
 Data inputs 
 
 Source Settings: -Loxx's Expanded Source Types. You typically use "open" since open has already closed on the current active bar
 LastBar - bar where to start the prediction
 PastBars - how many bars back to model
 LPOrder - order of linear prediction model; 0 to 1
 FutBars - how many bars you want to forward predict
 
 Things to know 
 
 Normally, a simple moving average is calculated on source data. I've expanded this to 38 different averaging methods using Loxx's Moving Avreages.
 This indicator repaints
 
 Related Indicators (linear extrapolation of price)  
 Levinson-Durbin Autocorrelation Extrapolation of Price 
  
 Weighted Burg AR Spectral Estimate Extrapolation of Price 
  
 Helme-Nikias Weighted Burg AR-SE Extra. of Price  
 
Spectralestimate
Helme-Nikias Weighted Burg AR-SE Extra. of Price [Loxx]Helme-Nikias Weighted Burg AR-SE Extra. of Price    is an indicator that uses an autoregressive spectral estimation called the Weighted Burg Algorithm, but unlike the usual WB algo, this one uses Helme-Nikias  weighting. This method is commonly used in speech modeling and speech prediction engines. This is a linear method of forecasting data. You'll notice that this method uses a different weighting calculation vs Weighted Burg method. This new weighting is the following:
w = math.pow(array.get(x, i - 1), 2),  the squared lag of the source parameter 
and 
w += math.pow(array.get(x, i), 2),  the sum of the squared source parameter 
This take place of the rectangular, hamming and parabolic weighting used in the Weighted Burg method
Also, this method includes Levinson–Durbin algorithm. as was already discussed previously in the following indicator:
Levinson-Durbin Autocorrelation Extrapolation of Price  
  
 What is Helme-Nikias Weighted Burg Autoregressive Spectral Estimate Extrapolation of price?  
In this paper a new stable modification of the weighted Burg technique for autoregressive (AR) spectral estimation is introduced based on data-adaptive weights that are proportional to the common power of the forward and backward AR process realizations. It is shown that AR spectra of short length sinusoidal signals generated by the new approach do not exhibit phase dependence or line-splitting. Further, it is demonstrated that improvements in resolution may be so obtained relative to other weighted Burg algorithms. The method suggested here is shown to resolve two closely-spaced peaks of dynamic range 24 dB whereas the modified Burg schemes employing rectangular, Hamming or "optimum" parabolic windows fail. 
 Data inputs 
 
 Source Settings: -Loxx's Expanded Source Types. You typically use "open" since open has already closed on the current active bar
 LastBar - bar where to start the prediction
 PastBars - how many bars back to model
 LPOrder - order of linear prediction model; 0 to 1
 FutBars - how many bars you want to forward predict
 
 Things to know 
 
 Normally, a simple moving average is calculated on source data. I've expanded this to 38 different averaging methods using Loxx's Moving Avreages.
 This indicator repaints
 
 Further reading 
 A high-resolution modified Burg algorithm for spectral estimation
 
 Related Indicators 
 Levinson-Durbin Autocorrelation Extrapolation of Price    
  
 Weighted Burg AR Spectral Estimate Extrapolation of Price    
 

