计数 · 同一个问题的三种答案
这个问题听起来只有一个答案，其实有三个，而且三个都站得住——差别在于地支里藏的干算多少权重。本页把同一张盘在三种口径下全部算出来，然后说清楚这个答案能用来做什么、不能用来做什么。
The example chart is 1985-07-04 12:00 (乙丑 Yi Chou · 壬午 Ren Wu · 甲辰 Jia Chen · 庚午 Geng Wu). Every number below is computed:
| 计数口径 | 木 Wood | 火 Fire | 土 Earth | 金 Metal | 水 Water |
|---|---|---|---|---|---|
| 只数显式干支（8 字） | 2 | 2 | 2 | 1 | 1 |
| 含藏干、半权（0.5） | 2.5 | 3 | 4 | 1.5 | 2 |
| 含藏干、全权（1.0） | 3 | 2 | 4 | 2 | 3 |
The bolded cell is the lowest count under that convention. Note that the set of least-present elements is not the same across the three rows — which is exactly why the question has to be asked before it is answered.
A second reading of missing is rare. Unfold all sixty day pillars and count how often each element appears as the day stem, and as the main qi of the day branch:
| 位置 | 木 Wood | 火 Fire | 土 Earth | 金 Metal | 水 Water |
|---|---|---|---|---|---|
| 日干（10 干 × 6） | 12 | 12 | 12 | 12 | 12 |
| 日支本气（12 支 × 5） | 10 | 10 | 20 | 10 | 10 |
As a day stem the five elements are exactly even, twelve each, because the ten stems pair into the five elements. As the day branch main qi, Earth appears 20 times against 10 for each other element: the four Earth branches are a third of the twelve. So "I am missing Earth" is the hardest claim to make at this level.
The popular version jumps from "what is missing" straight to "which coloured stone to wear and which way to sleep". There is no reproducible step in that jump: turning a count into a prescription requires inserting something the classical conventions never contained. This site publishes the first half — the counts, the conventions, the differences — and declines the second. Asking which element is useful for a chart is a different question with published rules of its own (the balance and climate schools, on the favourable-element page); it is not the same question as what is missing.
Enter a birth date to see all three conventions at once, with the lowest element under each. Leave the hour empty if unknown.
本页刻意不做的事：网上流传的通俗版本会给每个名目指派一套固定性格——一个地支一种人、一个阶段一种命。本站拒绝这种写法。这里发布的是一个结构位置：谁的五行坐在哪里、坐在什么样的地基上、地基里藏着什么。同一个名目在不同的月令之下读法不同；缺少盘中其余各字时，任何有意义的判断都不存在。凡传统给出读法之处，本页标注「此为传统读法」；本站自己的贡献是：页面上的每个数字与名目都由引擎实算、带版本号，可与方法论页逐条对账。
以下是本页独有的问题；更通用的口径问题见方法论页。
本站把八字里可穷举的构件都拆成了独立的页：每一页的事实都由同一个引擎实算，可逐条核对，不是人格对照表。