RSI(close; period)

The 'close' argument is an array that contains the close prices.
The 'period' parameter defines the period for the calculations - it must be a constant greater or equal to 1.

The result is an array. The first 'period' elements of the result are marked as invalid.

Relative Strength Index (RSI) is a popular momentum oscillator developed by J. Welles Wilder. The Relative Strength Index compares upward movements in closing price to downward movements over a selected period. The RSI ranges between 0 and 100. The formula of the RSI is:

RSI[n] = 100 - (100 / (1 + U[n] / D[n]))

where:

U[n] - average value of the upward price change for the given period
D[n] - average value of the downward price change for the given period

Relative Strength Index is smoother than the Momentum or Rate of Change oscillators and is not as susceptible to distortion from unusually high or low prices at the start of the window.

Windows Forms: All Examples\Data Manipulation\Functions\Financial\Technical Price Indicators