This point is specified by the location where you release the mouse after dragging it to create the circle. A good way to test both of these options is to try them on a uniform flow. Note, however, that they will work on any flow, however complex. The third button 'Show Mapping' enables you to modify the flow you have generated using conformal mapping, as discussed below. The Mapping Window Pressing the 'Show Mapping' button in the Ideal Flow Machine window brings up a second window in which you can explore elementary conformal mapping techniques.
Conformal mapping is an advanced topic, usually taught to seniors or graduates.
This description is a very natural one. We can therefore describe any 2D flow as a function of z. The problem with this result is that one does not know a priori which function of z will produced the specific flow of interest. The description of ideal flows in terms of complex numbers, however, allows for an additional route - the distortion of one flow into another by conformal mapping. At points where the derivative is zero, termed critical points, the mapped flow is not valid.