Guides

Alligator

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Indicator Tutorial 12

The Alligator is a classic indicator based on the idea that markets spend most of their time in a horizontal motion and about 15-30% of the time trending. Different interactions of its three SMA plots are said to help identify a coming trend and predict its direction. Here’s the basic definition:

  • The Jaws are a 13 period SMA shifted into the future by 8 bars.
  • The Lips are an 8 period SMA shifted into the future by 5 bars.
  • The Teeth are a 5 period SMA shifted into the future by 3 bars.

Using the Indicator’s shifts property, and the builtin SMA tool, we can easily accomplish the Alligator. shifts allow us to define bar-offsets on the X axis into the past or future on a plot-by-plot basis.

1const predef = require("./tools/predef");
2const SMA = require("./tools/SMA");
3
4class Alligator {
5    init() {
6        this.jaws = SMA(this.props.jaws)
7        this.lips = SMA(this.props.lips)
8        this.teeth = SMA(this.props.teeth)
9    }
10
11    map(d) {
12        const jaws = this.jaws(d.value())
13        const lips = this.lips(d.value())
14        const teeth = this.teeth(d.value())
15        return {
16            jaws, lips, teeth
17        }
18    }
19}
20
21module.exports = {
22    name: "Alligator",
23    description: "Alligator",
24    calculator: Alligator,
25    params: {
26        jaws: predef.paramSpecs.period(13),
27        lips: predef.paramSpecs.period(5),
28        teeth: predef.paramSpecs.period(8)
29    },
30    plots: {
31        jaws: { title: 'Jaws' },
32        lips: { title: 'Lips' },
33        teeth: { title: 'Teeth' }
34    },
35    tags: [predef.tags.MovingAverage],
36    schemeStyles: {
37        dark: {
38            jaws: { color: 'blue' },
39            lips: { color: 'green' },
40            teeth: { color: 'red' }
41        }
42    },
43    //we can use shifts to offset our bars. Negative values would be into the past.
44    shifts: {
45        jaws: 8,
46        lips: 5,
47        teeth: 3
48    }
49};

The Alligator indicator in action.