Smoothed Moving Average (SMMA) - Built-in Indicator Guide

Smoothed Moving Average (SMMA) that applies a recursive smoothing to price data.

Overview

The Smoothed Moving Average (SMMA) is a recursive moving average that reduces noise by applying exponential smoothing that weights recent data more heavily but updating the average gradually. It is designed for traders who want a smoother trend-following line that reacts less to short-term fluctuations than a simple moving average. On the chart, a single purple line is plotted directly over price. The line represents the current SMMA value of the chosen source (default close).

How it works

1. The indicator accepts a length (integer, default 7) and a src price source (default close).
2. It calls Rma.new(src, length) which creates a recursive moving average series.
3. The current bar’s value is obtained with [0] and returned as the plot output.
4. The Rma algorithm computes: SMMA = (previous SMMA * (length - 1) + src) / length, starting with a simple average of the first length bars.
5. The result is plotted as a continuous line on the main chart pane.

Mathematical model

The initial value is the simple average of the first length bars.

Parameters

Code walkthrough

Imports and dependencies

Lines 2-3 of Smoothed Moving Average.indie5:

from indie import indicator, param, source, plot, color
from indie.algorithms import Rma

The indicator imports the necessary decorators and the Rma algorithm from the built-in library. Rma implements the recursive smoothing logic, so the indicator itself only needs to call it.

Decorators for indicator metadata and parameters

Lines 6-9 of Smoothed Moving Average.indie5:

@indicator('SMMA', overlay_main_pane=True)  # Smoothed Moving Average
@param.int('length', default=7, min=1)
@param.source('src', default=source.CLOSE, title='Source')
@plot.line(color=color.PURPLE)

The @indicator decorator sets the display name ‘SMMA’ and places the plot in the main price pane. @param.int and @param.source define user-configurable inputs: a length (minimum 1) and a price source. @plot.line sets the line color to purple.

Main function – single-line computation

Lines 10-11 of Smoothed Moving Average.indie5:

def Main(self, length, src):
    return Rma.new(src, length)[0]

The Main function receives the parameters and returns the current value of the Rma series. Rma.new(src, length) creates the series, and [0] fetches the value for the current bar. The returned value is automatically plotted as a line.

Reading the chart

• The purple line represents the smoothed moving average of the selected source.
• When price is above the line, it may indicate an uptrend; below the line, a downtrend.
• The line itself is smoother than a simple moving average of the same length, making trend changes appear later but with fewer false signals.
• The line is continuous; no gaps or markers are drawn.

Implementation notes

• The indicator relies on the Rma algorithm, which maintains internal state across bars (previous SMMA value).
• The first length bars may produce NaN or incomplete values until the initial simple average is computed.
• Changing the length parameter recalculates the entire series; no partial updates.
• The indicator is overlaid on the main chart pane, so it scales with price.

FAQ

How do I change the color of the SMMA line?

Modify the color argument in the @plot.line decorator (line 9) to any supported color constant, e.g., color.RED.

What is the difference between SMMA and SMA?

SMA gives equal weight to each bar in the window and resets each bar. SMMA (Rma) is recursive: it incorporates the previous average, making it smoother and more responsive to longer-term trends.

Can I use a source other than close?

Yes. The src parameter accepts any price source (open, high, low, close, hl2, etc.). Change it in the indicator settings or by modifying the @param.source default.

Full source code

Indie Script v5, the built-in indicator as shipped with TakeProfit. Add it from the indicators menu or copy the code into the platform’s script editor.

# indie:lang_version = 5
from indie import indicator, param, source, plot, color
from indie.algorithms import Rma


@indicator('SMMA', overlay_main_pane=True)  # Smoothed Moving Average
@param.int('length', default=7, min=1)
@param.source('src', default=source.CLOSE, title='Source')
@plot.line(color=color.PURPLE)
def Main(self, length, src):
    return Rma.new(src, length)[0]