Start with the top line
Begin with Qian: six unbroken yang lines. Turn only the top line into yin and the figure becomes Guai, hexagram 43. Its upper trigram changes from Heaven to Lake; the lower trigram remains Heaven. The visual change is small enough to follow with your eyes.
The first line is at the bottom
Lines are numbered from bottom to top. Each group of three forms a trigram, and a pair forms a hexagram. The traditional King Wen numbers are an ordering of the 64 figures, not a binary reading of the six lines.
Three ways to look again
The nuclear figure uses original lines 2–3–4 below and 3–4–5 above. The complementary figure flips every yin and yang line; the reversed figure turns the six-line sequence upside down. These operations answer different structural questions and may sometimes produce the same figure.
Explore a structure, keep the distinction
Hexagram names and brief classical quotations come from the supplied I Ching text. Plain-language observations are NineHound’s explanations of the diagram. This playground does not cast a random reading or turn a line change into a prediction about your life.