27.11.2 Modifying Adaption Marks

The adaption marks are the identifiers that designate whether a cell should be refined, coarsened, or neutral. The operations used for modifying the adaption marks are:

• Exchange: It changes the cells marked for refinement into cells marked for coarsening, and all cells originally marked for coarsening into cells marked for refinement. This operation is applied to adaption registers that have only refinement marks.

  For example, the exchange operation can be used to coarsen a rectangular region. First, create an adaption register that marks a rectangular region of cells for refinement. Then use the Exchange operation to modify the cell marks, creating a rectangular region with cells marked for coarsening.

• Invert: This operation can only be used with mask registers. It toggles the mask markings, i.e., all cells marked ACTIVE are switched to INACTIVE, and all cells marked INACTIVE are switched to ACTIVE.

  For example, if you generate a mask that defines a circular region, you can quickly modify the mask to define the region outside of the circle using the Invert operation.

• Limit: This operation applies the present adaption volume limit to the selected adaption register. For information on adaption limits, see Section  27.12. You generally use this operation to determine the effect of the present limits on the adaption process. You can use the volume limit to create a uniform mesh by setting the limit to refine only the large cells. After all the cells have reached a uniform size, you can continue the refinement process to the desired resolution.

• Fill: This operation marks the cells in the adaption register that are not marked for refinement. You can use the Fill operation to combine multiple registers to make a new register.

  Notes: 1. When you combine registers, a cell will be marked for coarsening only if it is marked for coarsening in all of the registers.

  2. If you create an adaption register with an operation that only marks cells for refinement, but you do not want to prohibit coarsening, use the Fill operation before combining the register with any other registers.

The process for modifying adaption marks is as follows:

1.   Choose the register(s) in the Registers list.

2.   Click on the Exchange, Invert, Limit, or Fill button under Mark Actions.