relativeStrengthIndex() function

The relativeStrengthIndex() function measures the relative speed and change of values in an input table.

relativeStrengthIndex(
  n: 5,
  columns: ["_value"]
)

Relative strength index 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.

Parameters

n

(Required) The 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 (<-).

Output tables

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

Examples

The following example uses data provided by the sampledata package to show how relativeStrengthIndex() transforms data.

Calculate a three point relative strength index

import "sampledata"

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