compute_synastry
Compare two sidereal charts to find every graha-to-graha aspect, with type, orb, and strength. Uses only longitudes, so synastry works without birth times or places.
Instructions
Compute synastry — the aspects each graha in one chart makes to each graha in another chart. Every graha in chart A is tested against every graha in chart B (the two charts do not need the same graha names), and each hit is returned with its aspect type, orb in degrees and strength (1.0 at exact, falling linearly to 0.0 at the orb boundary). Orbs are the traditional Lilly values — conjunction, trine and opposition 8°, square 7°, sextile 6°, minors 2° — scaled by orb_factor. Longitudes only: this tool needs no birth time, place or ephemeris.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| chart_a | Yes | Map of graha name to sidereal longitude [0, 360) for the first chart, e.g. {"Sun": 10.0, "Moon": 130.0}. | |
| chart_b | Yes | Map of graha name to sidereal longitude [0, 360) for the second chart. Need not use the same names as chart_a. | |
| aspect_set | No | 'major' (default) tests the five Ptolemaic aspects; 'all' adds semi-sextile, semi-square, quintile, sesquiquadrate, bi-quintile and quincunx. | major |
| orb_factor | No | Multiplier on the default orbs. 1.0 (default) is standard, 0.5 is tight. Must be greater than 0 and at most 5.0, above which the major-aspect windows cover every separation. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| aspects | Yes |