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Radix Chart

Radix Chart

Section titled “Radix Chart”

A radix chart (also called a natal or birth chart) is a snapshot of the sky at a specific moment in time. It shows the positions of planets and house cusps for a particular birth location.

AstroChart renders radix charts from an AstroData object containing:

  • Planets — Positions as degrees (0–360), keyed by planet name
  • House Cusps — Exactly 12 degree values representing houses 1–12

Basic Radix Chart

Section titled “Basic Radix Chart”

Here’s the simplest example:

import { Chart } from '@astrodraw/astrochart'


const data = {
  planets: {
    Sun:  [12.45, 0],
    Moon: [145.67, 0]
  },
  cusps: [315.45, 35.67, 65.23, 92.45, 125.67, 155.89,
          135.45, 215.67, 245.23, 272.45, 305.67, 335.89]
}


const chart = new Chart('chart', 600, 600)
chart.radix(data)

Data Format

Section titled “Data Format”

Planets

Section titled “Planets”

Planets are stored in a key-value object (Record<string, number[]>):

planets: {
  Sun: [degrees, velocity]
  //    ^^^^^^^ 0–360
  //           ^^^^^^^^ optional: astrological velocity — negative = retrograde, positive or omitted = direct
}

Valid planet names:

  • Personal: Sun, Moon, Mercury, Venus, Mars
  • Social: Jupiter, Saturn
  • Generational: Uranus, Neptune, Pluto
  • Points: Chiron, Lilith, NNode (North Node), SNode (South Node), Fortune

House Cusps

Section titled “House Cusps”

Cusps must be an array of exactly 12 degree values:

cusps: [
  315.45,  // 1st house cusp (Ascendant)
  35.67,   // 2nd house cusp
  65.23,   // 3rd house cusp
  92.45,   // 4th house cusp (IC)
  125.67,  // 5th house cusp
  155.89,  // 6th house cusp
  135.45,  // 7th house cusp (Descendant)
  215.67,  // 8th house cusp
  245.23,  // 9th house cusp
  272.45,  // 10th house cusp (MC)
  305.67,  // 11th house cusp
  335.89   // 12th house cusp
]

Passing fewer or more than 12 cusps will throw a validation error.

Full Example with All Planets

Section titled “Full Example with All Planets”

Here’s a complete example with all 15 standard planets and points:

import { Chart } from '@astrodraw/astrochart'


const data = {
  planets: {
    Sun:     [12.45, 0],    // direct
    Moon:    [145.67, 0],
    Mercury: [8.23, 0],
    Venus:   [35.12, 0],
    Mars:    [162.34, 0],
    Jupiter: [298.56, 0],
    Saturn:  [245.78, 0],
    Uranus:  [178.90, 0],
    Neptune: [210.12, 0],
    Pluto:   [238.34, 0],
    Chiron:  [125.67, 0],
    Lilith:  [145.23, 0],
    NNode:   [95.45, 0],    // North Node
    SNode:   [275.45, 0],   // South Node
    Fortune: [325.67, 0]
  },
  cusps: [
    315.45, 35.67, 65.23, 92.45, 125.67, 155.89,
    135.45, 215.67, 245.23, 272.45, 305.67, 335.89
  ]
}


const chart = new Chart('chart', 600, 600)
chart.radix(data)

Retrograde Planets

Section titled “Retrograde Planets”

A planet is retrograde when its astrological velocity is negative. Pass the velocity as the second element of the array — the library automatically renders an R symbol next to retrograde planets:

const data = {
  planets: {
    Mercury: [8.23, -1.5],  // retrograde (negative velocity)
    Venus:   [35.12, 1.2],  // direct (positive velocity)
    Jupiter: [298.56, -0.3], // retrograde (negative velocity)
  },
  cusps: [ /* 12 values */ ]
}

Adding Aspects

Section titled “Adding Aspects”

Call .aspects() on the returned Radix instance to draw aspect lines between planets:

const chart = new Chart('chart', 600, 600)
const radix = chart.radix(data)
radix.aspects()  // draws conjunction, square, trine, opposition lines

Aspects are calculated automatically using default orbs:

  • Conjunction: 10°
  • Square: 8°
  • Trine: 8°
  • Opposition: 10°

You can customize orbs via Settings.

Interactive Demo

Section titled “Interactive Demo”

See a complete radix chart in action:

API Reference

Section titled “API Reference”

chart.radix(data: AstroData): Radix

Section titled “chart.radix(data: AstroData): Radix”

Renders a radix chart and returns a Radix instance for further operations.

Parameters:

  • data — AstroData object with planets (object) and cusps (array of 12 numbers)

Returns: Radix instance

Methods on Radix:

  • aspects() — Draw aspect lines between planets
  • transit(data) — Overlay a transit ring
  • on(eventName, callback) — Add click/hover listeners

Next Steps

Section titled “Next Steps”