Use a better way of integrating over the pixel area in the sample function. Ensure that the position angle is always between zero and 180 degrees, and that the widths are always positive. The default GaussianShape is at the J2000 North Pole with a width of 1 arc-min on both axes. The copy constructor uses copy semantics. The assignment operator uses copy semantics.
All numerical values are in radians.
There are also functions in the base class for doing this with other angular units. The reference frame and pixel size must be the same for all the specified directions. The w component is not used in these functions. The reference position for the transform is the direction of the component. As this component is symmetric about this point the transform is always a real value.