**LNRet: Indicator Documentation**

**Syntax**

public LNRet(Bars bars, DataSeries ds, int period)
public LNRet(Bars bars, DataSeries ds, int period, string description)

**Parameter Description**

*bars* | A Bars object |

*ds* | Data series |

*period* | Lookback period |

**Description**

The LNRet function is used for computing logarithms of daily returns. Translated to C# from legacy version by Dr. Rene Koch.

```
logarithm of daily returns.
```

Z(t) := ln(Y(t)) - ln(Y(t - lookback))

or equivalently:

Z(t) := ln(Y(t) / Y(t - lookback))

**Remarks**Logarithmic returns are the "base currency" in quantitative analysis. Unlike arithmetic returns:

- logarithmic returns sum in a correct way: the sum of five logarithmic daily returns is the same as the weekly log return.
- the natural log return is the equivalent of the
*continuously compounded rate of return* for the given time period.

Logarithmic returns are the base of most further calculations:

- CAGR - Compound Annualized Geometric Return
- HV - Historical Volatility
- Variance Ratios

**See also**- ROC - absolute returns as percentages
- MomentumPct - relative returns as percentages
- Momentum - Difference of Prices. Depends on absolute price level.