relativeStrengthIndex() function

relativeStrengthIndex() measures the relative speed and change of values in input tables.

Relative strength index (RSI) rules

• The general equation for calculating a relative strength index (RSI) is RSI = 100 - (100 / (1 + (AVG GAIN / AVG LOSS))).
• For the first value of the RSI, AVG GAIN and AVG LOSS are averages of the n period.
• For subsequent calculations:
  • AVG GAIN = ((PREVIOUS AVG GAIN) * (n - 1)) / n
  • AVG LOSS = ((PREVIOUS AVG LOSS) * (n - 1)) / n
• relativeStrengthIndex() ignores null values.

Output tables

For each input table with x rows, relativeStrengthIndex() outputs a table with x - n rows.

Function type signature

(<-tables: stream[A], n: int, ?columns: [string]) => stream[B] where A: Record, B: Record

Parameters

n

(Required) Number of values to use to calculate the RSI.

columns

Columns to operate on. Default is ["_value"].

tables

Input data. Default is piped-forward data (<-).

Examples

Calculate a three point relative strength index

import "sampledata"

sampledata.int()
    |> relativeStrengthIndex(n: 3)