# Technical Studies Reference

- Technical Studies Reference
- Common Study Inputs (Opens a new page)
- Using Studies (Opens a new page)

### Ergodic

This study calculates and displays Bill Blau's Ergodic indicator, also known as the True Strength Index. This study calculates 3 lines, the Ergodic (True Strength Index), the Ergodic Signal Line (exponential moving average of the TSI), and the Ergodic Oscillator (Difference of Signal and TSI). Only the first is displayed, but the others can be displayed by going through **Settings >> Subgraphs >> Draw Style** and changing the setting to anything other than **Ignore**.

Let \(X\) be a random variable denoting the **Input Data**, and let the **Long MovAvg Length**, **Short MovAvg Length**, **Signal Line MovAvg Length**, and **Multiplier** Inputs be denoted as \(n_L\), \(n_S\), \(n_{Sig}\), and \(v\), respectively. We denote the **Ergodic**, **Ergodic Signal Line**, and **Ergodic Oscillator** at Index \(t\) for the given Inputs as \(TSI_t(X,n_L,n_S,v)\), \(\overline{TSI}_t(n_L,n_S,n_{Sig},v)\), and \(TSIOsc_t(X,n_L,n_S,n_{Sig},v)\), respectively, and we calculate them in terms of Exponential Moving Averages as follows.

In the above formula, \(\Delta X_t = X_t - X_{t - 1}\) is calculated for \(t \geq 1\), the first EMA is calculated for \(t \geq n_L - 1\), and the second EMA is calculated for \(t \geq n_L + n_S - 2\).

\(\overline{TSI}_t(X,n_L,n_S,n_{Sig},v) = EMA_t(TSI(X,n_L,n_S,v), n_{Sig})\)\(TSIOsc_t(X,n_L,n_S,n_{Sig},v) = TSI_t(X,n_L,n_S,v) - \overline{TSI}_t(X,n_L,n_S,n_{Sig},v)\)

Each of the above is calculated for \(t \geq n_L + n_S + n_{Sig} - 3\).

**Note**: Depending on the setting of the Input **MovAvg Type**, the Exponential Moving Averages in the above formulas could be replaced with Linear Regression Moving Averages, Simple Moving Averages, Weighted Moving Averages, Wilders Moving Averages, Simple Moving Averages - Skip Zeros, or Smoothed Moving Averages.

#### Inputs

- Input Data
- MovAvg Type
- Long MovAvg Length
- Short MovAvg Length
**Multiplier**: An optional multiplier can be used for extremely small values.- Signal Line MovAvg Length

#### Spreadsheet

The spreadsheet below contains the formulas for this study in Spreadsheet format. Save this Spreadsheet to the Data Files Folder.

Open it through **File >> Open Spreadsheet**.

*Last modified Friday, 13th July, 2018.