Zhouyi casting glossary
Definitions, levels and sources for lines, hexagram relations, eight palaces, Najia, Six Relations and host/response.
Hexagrams and lines
A line is a basic yin or yang stroke. Three lines form a trigram; two stacked trigrams form a six-line hexagram. Line positions on this site are always counted from bottom to top.
Hexagram judgments and line texts
The judgment appears at the beginning of a hexagram; line texts correspond to its six positions. This site identifies both as classical text, separate from later interpretations.
Tuan and Xiang commentaries
The Tuan commentary explains the judgment. The Xiang commentary includes the Great Image on the hexagram and Small Images on individual lines. Result pages place these commentaries after the classical text and identify their sources.
Changing line
Among casting values, 6 is old yin and 9 old yang. The site marks both as changing lines: 6 changes to yang and 9 to yin. 7 and 8 are unchanging lines.
Primary and resulting hexagrams
The primary hexagram is the original six lines obtained in the cast. The resulting hexagram changes the polarity of its changing lines. With no changing lines, no separate resulting hexagram is listed.
Complementary, inverted and nuclear hexagrams
The complementary hexagram reverses every line’s polarity; the inverted hexagram reverses the six-line order. The nuclear hexagram takes lines 2, 3, 4 as its lower trigram and 3, 4, 5 as its upper trigram. These are structural derivations, not new casts.
Three changes form one line
Each yarrow line involves three rounds of dividing into two heaps, setting aside one stalk, counting in fours and collecting the remainders. Six lines total 18 changes. This site saves the stalk-count trace for each change.
Modulo 8 for trigrams, modulo 6 for lines
Meihua Yishu number calculation uses modulo 8 to choose a trigram and modulo 6 to choose a changing line. A zero remainder is treated as 8 and 6 respectively.
Eight palaces
Jing-school Yi studies assign the 64 hexagrams to the eight palaces Qian, Zhen, Kan, Gen, Kun, Xun, Li and Dui. Each palace has its base hexagram, first through fifth generations, Wandering Soul and Returning Soul in sequence.
Najia
A later image-and-number system that assigns Heavenly Stems and Earthly Branches in fixed order to the six-line positions associated with the eight trigrams. The Najia page is separate from the Zhouyi classical-text and commentary reading layer.
Six relations
Using the palace’s Five Phase as the reference, each line branch’s phase is classified by generating, controlling or same-phase relationships into Parents, Siblings, Descendants, Wife and Wealth, or Officer and Ghost. These labels are not automatic identifications of blood relatives.
Host and response lines
Later chart markers place the host and response at fixed line positions in the eight-palace sequence. This site uses its published tables, not the names alone, and does not generate predictions directly from these markers.
Zodiac animals and year branches
The 12 zodiac animals have fixed correspondences with the 12 Earthly Branches, from Zi–Rat and Chou–Ox to Hai–Pig. This site uses that mapping only to label a birth year’s branch, not to infer personality, destiny or relationship outcomes from animal names.
Folk zodiac year
The site’s default zodiac convention converts a Gregorian date to a lunar date and changes the zodiac year on the first day of the first lunar month. This is not a January 1 year boundary.
Year-pillar convention: Lichun boundary
Later Four Pillars traditions often change the year pillar at the exact Lichun solar-term instant. This site requires birth time and an IANA time zone, converts local time to the same instant and compares the transition to the second. It explicitly does not calculate apparent solar time.
Lunar leap month
An extra month reconciles synodic months with the tropical year; it does not occur every year. A regular month and its same-number leap month are different months. Input must verify the year, leap-month number and actual day count together.
Six branch combinations and six clashes
Six combinations and six clashes each consist of six fixed branch pairs. The zodiac page lists matching pairs only. It does not adopt specific fortune judgments from the sources or equate a clash with relationship failure.
Six clash pairs
Zi–Wu, Chou–Wei, Yin–Shen, Mao–You, Chen–Xu and Si–Hai are the six fixed clash pairs. This structural fact is kept separate from six-line divinatory interpretation; clashing year branches do not generate event predictions here.
Six harm pairs
Zi–Wei, Chou–Wu, Yin–Si, Mao–Chen, Shen–Hai and You–Xu are the six harm pairs listed in later traditions. This site lists only the fixed pairs, not the original works’ judgments about people, illness or fortune.
Editorial limits
Definitions explain this site’s data and calculation conventions, not original source passages. Classical quotations retain their original character forms. Where later traditions differ by school, only sourced parts implemented on this site are included.