Meridian is the direction indicated by the earthly branch: purple water means true north. The midday flame points due south. These two directions belong to Yang.
The deck is the direction indicated by the sky, and the water indicates the north. Ding Huo showed the south. Both directions belong to yin.
Meridional direction is due to the north-south direction, but also to the mountain direction, that is, slightly deviated from the positive direction, which is not the most correct noon direction in Zi Shan.
Meridional direction is due to the north-south direction, but also to the mountain direction, that is, slightly deviated from the positive direction, which is not the most correct noon direction in Zi Shan.
From feng shui.