1-7-trigrams

Qián-Gěn, Heaven-Mountain

When Qián changes to Gěn, the individual becomes aware of anything that is not in accordance with the heavenly laws and turns away from it. When too close to judge, too close to remain free or clean, too close to danger or to harmful things or people, too close to oversee, then it is better to withdraw and take control of your situation and regain power over your life and mind.

This is the short answer - click for the complete one.

The initiative

trigram Heaven
The top line (Heaven-line) shows the change of the focus or initiative.

The top line is stationary yang. A yang initiative, entering a yang world, fits right in. Both clear and inspiring, full of plans. Even when other things change, you will remain giving, pouring ideas, efforts or money into this situation. Yang brings and spreads creativity and ideas with a good basic structure, It is the master of good timing and planning, but not of finding a final solution or concrete results.
Stay within limits, Yang is also prone to deplete itself. It is relentless, and it can focus so intensely on mental images that they can turn into air castles or delusions. Yin is necessary for concrete results but not before the planning is right, too early can be disastrous, no matter the quality of your ideas or how determined you are.

Yang has the talent to enjoy the road
before reaching any destination.

The initiative

trigram Heaven Heaven

The top line (Heaven-line) shows the initiative now and its change.

The top line is unchanging yang. The initiative remains clear and inspiring, continuing with plans and monitoring the process. Even when other things change, you will remain giving, pouring ideas, efforts or money into this situation, but not yet finding a solution or concrete results.
Yang brings and spreads creativity and ideas with a good basic structure, but it is not yet the time to concretize them. Stay within limits, yang brings increase but is also prone to deplete itself, it is relentless, and it can also be so focused on mental images that they can turn into air castles or delusions.

The subject

The bottom line (Earth-line) shows the change of the field or subject.
变初九为巽为风。春风融和利物, 夏风散雨收云, 秋风物物收敛, 冬风寒水成冰。静正则吉, 往进则凶, 阴道须得志, 亦不可恃势妄作。
The bottom line activates Xun, activates the Wind. To be calm and indifferent to fame and gain, inclined to purity, is favorable. Wanting to go forward is unfavorable. The way of yin is striving for ambition. One cannot rely on one's position or influence or act recklessly or unethically.

The outcome

The middle line (Man-line) shows the outcome.
变九二为离为火。离为火为日, 吐焰发耀, 光照天下, 太阳之三三象，
长育之君, 万象贤明, 百物附丽。
The change of the middle yang line activates Li, which is fire and the sun, spewing flames and brightly radiant; its rays illuminate everything under the sky, its image is repeated eminent yang.
It is the ruler who brings greatness. The source of life and clarity for everything on Earth, all beings bind themselves to it.

General
When a middle line changes from yang to yin, it will lose its outward shine, but now things will proceed in a more tangible way. Resources will be used with a good plan of action to create concrete results. Things change from giving to absorbing, from ideas and inspiration to processing, from overviewing to being part of the work. And if there are problems, this change can be what you need.
It can also mean that it is time to pass the reigns to your guts and intuition instead of your head.

  Each line, active or at rest, summons one of the 8 trigrams as a Helper. For an activated line: telling you what you need - or about a problem area or something to avoid.
  For a stationary line: this is what you already have or do or what you don't need. Often we just need a reminder of our abilities. Or it could be what you wish or fear - but will not happen.
  Active lines are the helpers to change things. Stationary helpers are part of the core meaning, they are your soul talking. They reinforce the overall power of a reading.
  Advice for the initiative: Dui, Lake, with her ability to resonate and persuade, is lacking here or not needed. Yang remains Yang.
  Advice for the subject: Xun, Wind, with her power to choose and influence.
  Advice for the outcome: Li, Fire, with her power to discern and create order.
  But when things are not satisfying, it might be that one or more helpers don't help enough - or try too hard. Or maybe you don't listen carefully enough.