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Drawing a subdomain

The controls for creating subdomains are shown here:
There are two options for creating subdomains: you may press the Click SD Points button and then use the mouse to choose the vertex locations, or you may type the coordinates directly into the edit boxes.

If you use the Click SD Points button, you must click on 8 points to define a subdomain. When you finish clicking on all 8 points, their coordinates will appear in the vertex edit boxes and the subdomain outline will appear in the axes. Please note that at this stage, all edges appear as straight lines, but that may not be the case for the final mesh. Once the vertex locations appear in the edit boxes, you may alter them by hand if you need to make changes. Altering the coordinates by hand will not immediately update the image in the axes.

If you choose to type the coordinates directly into the edit boxes, do not press the Click SD Points button, as that will halt operation of the GUI until you choose 8 points with the mouse. Instead, just enter a value in each edit box. Tab moves to the next edit box. You may use notation such as `-1e6` or `1.2-cos(pi/4)` in the edit boxes, but avoid using spaces. When you enter vertex locations in the edit boxes, the domain may not appear in the axes immediately.

In addition to the vertex locations, you must also choose the number of divisions in both directions (Side 1-3 divs and Side 2-4 divs) by entering numbers in those edit boxes. The default value is 5 in each direction.

After choosing all values for the subdomain, press the Save SD button. That saves the vertex coordinates and number of divisions, updates the view in the axes, and brings up a question box, asking if you would like to add another subdomain. If you choose Yes, the vertex positions edit boxes will be cleared. You can then either use Click SD Points, or enter the values by hand, as before. If you want the new subdomain to be joined to the existing subdomains, be sure to match all three nodes on a side. You may add as many subdomains as you like, pressing the Save SD button after each one. Once you have drawn the entire domain, answer No when asked if you would like to add another subdomain.

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