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docs/SMA.md

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+# SMA: Simple Moving Average
+SMA is one of the most basic trend-following indicators used in Technical Analysis. It is calculated as the *unweighted mean* of the previous $p$ (period) data-points.
+
+
+## Calculation
+
+SMA is a rolling calculation looking backwards from the position ${n}$ and is denoted as ${SMA}_{p}{(data)}$ where $p$ represents the period and $data$ represents the list of data points:
+$$
+SMA_p{(data)} = \frac{1}{p}\sum_{i=n-p+1}^{n} data_i
+$$
+When calculating the value of next $SMA_{p,next}$ while knowing all previous SMA values, SMA calculation can be reduced to:
+$$
+SMA_{p,next} = SMA_{p,prev}+\frac{1}{p}\left( data_{n+1}-data_{n+1-p}\right)
+$$
+
+## Implementation
+
+``` csharp
+SMA_Series mean = new(source: data, period: p, useNaN: false);
+
+QuanTA fluent = data.SMA(period: p);
+```
+
+## Parameters
+
+- `TSeries source` -  List of value tuples (DateTime, double)
+- `int period` - Integer representing the period of SMA
+- `bool useNaN` - if true, initial values from 1 to period-1 will be replaced with NaN. If false, the initial calculation will return values for SMA(length) instead of SMA(period)
+
+## Sample chart
+
+picture of SMA
+
+## Comparison & Validation
+
+Validation tests
+Performance tests
+
+## References
+   - https://www.tradingtechnologies.com/help/x-study/technical-indicator-definitions/simple-moving-average-sma/