Encapsulates defocus of a electron micrograph, defined by two defocus values in Angstroem and the angle of astigmatism in radians.
returns astigmatism angle
returns defocus in x
returns defocus in y
returns mean defocus
sets astigmatism angle
sets defocus in x
sets defocus in y
sets mean defocus
initialization with defocus in x and y and astigmatism angle