Answer first
In the description used here, a Meihua calculation produces a structured sequence: two trigrams form a primary hexagram, a moving line identifies a changed figure, and the middle lines form a nuclear figure. The cited traditional framework relates the Body and Use trigrams through the Five Phases.
The traditional instructions cited below supply remainder-based trigram and moving-line rules plus nuclear and Body/Use methods. Sky Atlas applies those rules as a deterministic sequence. The value of the exercise lies in making a symbolic pattern inspectable; the arithmetic does not establish that a future event will occur.
Meihua and the Yijing are related, not identical
Meihua Yishu and the Yijing (易經) are related through a shared vocabulary of trigrams and six-line hexagrams, but the terms do not make the methods identical. The Meihua instructions cited here distinguish the eight trigrams from the names of sixty-four hexagrams. The cited Yijing excerpt is a named 同人 entry. Those sources establish textual overlap; they do not establish common authorship, an official lineage, or that a Meihua reading is a full Yijing commentary.
“Related” does not mean interchangeable. A Meihua result is not a complete Yijing commentary. This comparison is editorial context drawn from the two cited excerpts, not a historical claim about authorship or an official lineage.
How a structure is built
- 01 Choose a stated input.
This guide and the Sky Atlas implementation support a local date-time cast and a two-number cast. The engine uses no random source or private text question.
- 02 Derive the upper and lower trigrams.
The cited Volume One instruction divides a number by eight and uses the remainder to choose a trigram. A remainder of zero is read as the eighth trigram. The engine follows that stated sequence.
- 03 Select the moving line.
The cited rule divides the relevant total by six and uses the remainder to identify one of the six lines, counted from the bottom.
- 04 Derive the related figures.
The primary hexagram is the starting arrangement of the two cast trigrams. The cited nuclear rule uses the middle four lines. The changed figure is produced by flipping the selected line in this project's implementation.
- 05 Compare Body and Use.
The cited framework treats 體 and 用 as relational roles and discusses their Five-Phase generation and control. In this implementation, the trigram containing the moving line is Use and the other is Body. That assignment is disclosed project method, not a claim that every school uses the same convention.
本卦 Primary hexagramběn guà
The starting six-line figure formed directly from the upper and lower trigrams. It is a structural starting point, not a fixed life outcome.
互卦 Nuclear hexagramhù guà
A figure derived from primary lines 2–4 and 3–5. It is not an independent second cast. This project applies the general middle-line rule to every primary hexagram and records that implementation choice without asserting that every school follows the same convention.
变卦 Changed hexagrambiàn guà
The figure produced when the moving line changes polarity. “Changed” names a transformed symbol, not a guaranteed future event.
体用 Body and Usetǐ yòng
Traditional text describes this pair as 體為主，用為事 and uses Five-Phase generation and control to discuss favorable or unfavorable relations. Sky Atlas renders the pair as Body and Use for structural analysis. The roles are not “self versus enemy”; the project does not turn a traditional favorable or unfavorable label into a scientific measure or personal verdict. The Five Phases guide explains the relation vocabulary.
Reading the structure without overclaiming
This is Sky Atlas editorial synthesis, not a rule attributed to every Meihua school.
- Record the receipt.
State the input, cast method, source rule, and engine version before describing the symbols.
- Describe before interpreting.
Name the upper and lower trigrams, moving line, primary, nuclear, and changed figures.
- Keep the three figures distinct.
The primary is the starting arrangement, the nuclear figure is an internal view of its middle lines, and the changed figure marks the selected line's transformation. None is a competing forecast.
- State the relation.
Name the Body/Use assignment and the Five-Phase relation, then say whether that label comes from the cited text, the project's implementation, or your own reflection.
- Separate reflection from verification.
A prompt can organize attention, but it cannot verify a fact, predict an event, or choose a high-stakes course of action.
The practical standard is reproducibility: another reader should be able to reconstruct the same structure from the stated input and rules. The interpretation should remain visibly interpretive.
A worked example: 4 February 2024, 17:00
Calculated layer. The Sky Atlas engine, rule version meihua-number-time-v0.2, reports lunar year branch 4, lunar month 12, lunar day 25, and hour branch 10 for this civil date-time. Those fields produce an upper source of 41 and a lower source of 51. Their remainders after division by eight give Heaven above and Fire below. The lower source divided by six gives moving line three. The Chinese calendar guide explains the time layers used by the conversion.
Heaven above, Fire below · moving line 3
Middle lines form a second structure
Line 3 reverses from solid to broken
Project interpretation within the traditional framework. Upper Qian is Metal; the moving lower trigram Li is Fire. In this engine's Five-Phase sequence, Fire controls Metal, so it reports “Use controls Body.” That is a relation between structural roles, not a verdict about a person or decision.
What this does not mean
- The method does not establish a medical diagnosis or treatment.
- It does not decide a legal, immigration, financial, or relationship outcome.
- It does not predict accidents, death, pregnancy, or another person's intentions.
- A traditional symbolic relation is not a scientific measurement.
- “No verdict” does not mean the opposite verdict is hidden elsewhere.
High-stakes boundary. For medical care, legal rights, immigration status, financial decisions, fertility questions, or personal safety, use a qualified professional or the responsible official authority. Do not use a Meihua result as verification, emergency support, or the deciding record for such a decision. If someone may be in immediate danger, contact local emergency services.
The internal implementation defines fixed prompts about attention, pressure, support, and proportion. They are prompts for reflection, not instructions about what you should do or what will happen.
Sources and method note
- 《梅花易數》, Wikisource, accessed 2026-10-21. Volume one is used for trigram division, moving-line division, nuclear-figure construction, and date-time casting. Volume two is used for the Body/Use framework. These excerpts support the guide's traditional layer; they do not establish one school's universal authority.
- 《易經》, Project Gutenberg eBook #25501, accessed 2026-10-21. The cited excerpt contains the named 同人 entry. It is not used here to infer authorship, lineage, or the full textual history.
- Sky Atlas method note. The worked example is output from the project's deterministic Meihua engine, rule version meihua-number-time-v0.2. Calculated values, traditional instructions, disclosed implementation choices, and editorial synthesis are separate layers. See Sources and Access Dates for the project's source policy.
Source review: 2026-10-21. See corrections with a source or claim-layer issue.
Next step
Keep the tool and the guide distinct.
The cultural guide can remain available while the calculator is withheld for verification. No live calculation is offered here.
Read the methodologyAbout this guide and its links
Independence and self-links. Sky Atlas is independently published and edited by Zhou Zhe. It operates the cultural-portrait tool linked on this page, so that is a self-link rather than an independent endorsement. The guide is not an official Meihua school and has no sponsorship, paid placement, or affiliate relationship with Wikisource, Project Gutenberg, or any cited source. It also has no affiliation with any temple, lineage, academic body, certification organization, or regulator.