Chop Zone - Built-in Indicator Guide

Computes the slope angle of a 34-period EMA relative to the price range and colors a column to indicate trend strength and direction.

Overview

The Chop Zone indicator measures the steepness and direction of the trend by calculating the angle of a 34-period exponential moving average (EMA) relative to the recent price range. It is designed to help traders identify trending versus choppy or sideways market conditions, with color-coded columns indicating the strength of the trend.

On the chart, the indicator draws a vertical column at each bar with a fixed height of 1 price unit. The column’s color is determined by the computed angle: turquoise/green shades for upward trends, red/orange shades for downward trends, and yellow for near-flat conditions. The angle is derived from the normalized difference between consecutive EMA values, scaled by the 30-bar high-low range.

How it works

1. Compute the highest high and lowest low over the last 30 bars.
2. Calculate a scaling factor span = 25 / (highest_high - lowest_low) * lowest_low to normalize the EMA slope.
3. Calculate a 34-period EMA of the closing price and obtain the current and previous values.
4. Compute the normalized slope: (prev_EMA - curr_EMA) / hlc3 * span, where hlc3 is the average of high, low, and close.
5. Convert the absolute slope to an angle in degrees: angle = round(180/π * arctan(|slope|)).
6. Assign a negative angle for downward slopes (prev EMA > curr EMA) and positive for upward slopes.
7. Classify the angle into one of nine color bands using fixed thresholds (e.g., ≥5° → turquoise, ≤-5° → dark red, between -0.71° and 0.71° → yellow).
8. Draw a single column of height 1 at the current bar using the assigned color.

Mathematical model

Logic flow

flowchart TD
    A["Start new bar"] --> B["Compute highest_high, lowest_low (30)"]
    B --> C["Compute span"]
    C --> D["Compute EMA34[0], EMA34[1]"]
    D --> E["Compute slope and angle"]
    E --> F["Classify angle into color band"]
    F --> G["Draw column with color"]

Code walkthrough

Range and scaling factor

Lines 21-24 of Chop Zone.indie5:

    periods = 30
    highest_high = Highest.new(self.high, periods)[0]
    lowest_low = Lowest.new(self.low, periods)[0]
    span = divide(25, highest_high - lowest_low) * lowest_low

These lines calculate the 30-bar high and low range and derive a scaling factor span that normalizes the EMA slope relative to the price level and range. The divide function safely handles division by zero.

EMA and angle calculation

Lines 26-32 of Chop Zone.indie5:

    ema34 = Ema.new(self.close, 34)
    y2_ema34 = divide(ema34[1] - ema34[0], self.hlc3[0]) * span

    ema_angle_1 = nan
    if not isnan(y2_ema34):
        ema_angle_1 = round(180 * atan(abs(y2_ema34)) / pi)
    ema_angle = -ema_angle_1 if y2_ema34 > 0 else ema_angle_1

The 34-period EMA of the close price is computed. The difference between previous and current EMA is divided by the average price (hlc3) and multiplied by span to get a normalized slope. The angle in degrees is derived using arctan, and its sign is set negative for downward slopes (prev > curr).

Color classification

Lines 34-52 of Chop Zone.indie5:

    chop_zone_color = color.BLACK  # default value
    if ema_angle >= 5:
        chop_zone_color = color_turquoise
    elif ema_angle >= 3.57:
        chop_zone_color = color_dark_green
    elif ema_angle >= 2.14:
        chop_zone_color = color_pale_green
    elif ema_angle >= 0.71:
        chop_zone_color = color_lime
    elif ema_angle <= -5:
        chop_zone_color = color_dark_red
    elif ema_angle <= -3.57:
        chop_zone_color = color_red
    elif ema_angle <= -2.14:
        chop_zone_color = color_orange
    elif ema_angle <= -0.71:
        chop_zone_color = color_light_orange
    else:  # ema_angle > -0.71 and ema_angle < 0.71
        chop_zone_color = color_yellow

A series of conditional checks assigns a color based on the computed angle. The thresholds are fixed: angles >=5° indicate a strong uptrend (turquoise), angles <=-5° indicate a strong downtrend (dark red), and angles between -0.71° and 0.71° are considered flat (yellow). The color is used to draw the column.

Reading the chart

• The indicator draws a vertical column at each bar with a fixed height of 1 price unit.
• The column color indicates the trend strength and direction:
  • Turquoise: strong uptrend (angle ≥ 5°)
  • Dark green: moderate uptrend (3.57° ≤ angle < 5°)
  • Pale green: slight uptrend (2.14° ≤ angle < 3.57°)
  • Lime: very slight uptrend (0.71° ≤ angle < 2.14°)
  • Yellow: flat/sideways (-0.71° < angle < 0.71°)
  • Light orange: very slight downtrend (-2.14° < angle ≤ -0.71°)
  • Orange: slight downtrend (-3.57° < angle ≤ -2.14°)
  • Red: moderate downtrend (-5° < angle ≤ -3.57°)
  • Dark red: strong downtrend (angle ≤ -5°)
• The column is drawn at the current bar’s position; consecutive columns create a color-coded strip along the time axis.

Implementation notes

• The indicator uses a fixed 30-bar window for the high-low range and a 34-period EMA; these parameters are not user-adjustable in this version.
• The hlc3 series (average of high, low, close) is used as a denominator to normalize the slope relative to the price level.
• The angle calculation uses round() and integer thresholds, so small changes in slope may not produce a color change.
• If the high-low range is zero (e.g., flat price), divide returns nan, causing span to be nan and consequently the angle to be nan, which falls into the else branch and yields a yellow column.

FAQ

How can I adjust the sensitivity of the Chop Zone indicator?

The indicator uses fixed parameters (30-bar range, 34-period EMA, and angle thresholds). To modify sensitivity, you would need to edit the source code, changing periods, the EMA length, or the threshold values.

What does the column height represent?

The column height is fixed at 1 price unit. It does not represent any data value; it is merely a visual marker. The color alone conveys the trend information.

Can I change the color scheme?

Yes, you can modify the color definitions in the source code (lines 11-19) and the assignment logic (lines 34-52) to use your preferred colors.

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 math import nan, isnan, atan, pi
from indie import indicator, format, plot, color, Color
from indie.algorithms import Highest, Lowest, Ema
from indie.math import divide


@indicator('Chop Zone', format=format.PRICE, precision=0)
@plot.columns()
def Main(self):
    color_turquoise = color.rgba(38, 198, 218)
    color_dark_green = color.rgba(67, 160, 71)
    color_pale_green = color.rgba(165, 214, 167)
    color_lime = color.rgba(0, 150, 136)
    color_dark_red = color.rgba(213, 0, 0)
    color_red = color.rgba(233, 30, 99)
    color_orange = color.rgba(255, 109, 0)
    color_light_orange = color.rgba(255, 183, 77)
    color_yellow = color.rgba(253, 216, 53)

    periods = 30
    highest_high = Highest.new(self.high, periods)[0]
    lowest_low = Lowest.new(self.low, periods)[0]
    span = divide(25, highest_high - lowest_low) * lowest_low

    ema34 = Ema.new(self.close, 34)
    y2_ema34 = divide(ema34[1] - ema34[0], self.hlc3[0]) * span

    ema_angle_1 = nan
    if not isnan(y2_ema34):
        ema_angle_1 = round(180 * atan(abs(y2_ema34)) / pi)
    ema_angle = -ema_angle_1 if y2_ema34 > 0 else ema_angle_1

    chop_zone_color = color.BLACK  # default value
    if ema_angle >= 5:
        chop_zone_color = color_turquoise
    elif ema_angle >= 3.57:
        chop_zone_color = color_dark_green
    elif ema_angle >= 2.14:
        chop_zone_color = color_pale_green
    elif ema_angle >= 0.71:
        chop_zone_color = color_lime
    elif ema_angle <= -5:
        chop_zone_color = color_dark_red
    elif ema_angle <= -3.57:
        chop_zone_color = color_red
    elif ema_angle <= -2.14:
        chop_zone_color = color_orange
    elif ema_angle <= -0.71:
        chop_zone_color = color_light_orange
    else:  # ema_angle > -0.71 and ema_angle < 0.71
        chop_zone_color = color_yellow
    return plot.Columns(1, color=chop_zone_color)