﻿ RelativeStrengthIndex(Series,Int32) Method        dotnetCHARTING Send comments on this topic. RelativeStrengthIndex(Series,Int32) Method See Also Collapse All Expand All Language Filter: All Language Filter: Multiple Language Filter: Visual Basic (Declaration) Language Filter: Visual Basic (Usage) Language Filter: C#
 dotnetCHARTING Namespace > FinancialEngine Class > RelativeStrengthIndex Method : RelativeStrengthIndex(Series,Int32) Method

s
An series where the first element is the high in the last trading period, the second term is the high in the previous period and so on.
lengthOfPeriod
An integer which represents the length of the period over which the indicator will be iteratively evaluated.
Implements the Relative Strength Indicator (RSI), developed by J. Welles Wilder in 1978; which measures the relative internal strength of a market. Please note that this indicator is not measured against another market or index. RSI measures the relative changes between higher and lower closing prices.

# Syntax

Visual Basic (Declaration)
```Public Overloads Shared Function RelativeStrengthIndex( _
ByVal s As Series, _
ByVal lengthOfPeriod As Integer _
) As Series```
Visual Basic (Usage) Copy Code
``````Dim s As Series
Dim lengthOfPeriod As Integer
Dim value As Series

value = FinancialEngine.RelativeStrengthIndex(s, lengthOfPeriod)``````
C#
```public static Series RelativeStrengthIndex(
Series s,
int lengthOfPeriod
)```

#### Parameters

s
An series where the first element is the high in the last trading period, the second term is the high in the previous period and so on.
lengthOfPeriod
An integer which represents the length of the period over which the indicator will be iteratively evaluated.

# Remarks

### Evaluation

The RSI indicator is calculated by the following formula:

`RSI = 100 - 100/(1+RS)`,

where:

`RS = (Average of noOfPeriods days up closes) / (Average of noOfPeriods days' down closes)`,

### Interpretation

An RSI above 70 is considered overbought and below 30 is considered oversold.