Utility codes for various Mobius transformations.
If aa1,bb1,cc1,dd1 are the coefficients for one transformation, and aa2,bb2,cc2,dd2 are the coefficients for a second one, then the coefficients for the mapping of a test point, zz, by aa1 etc to zw, followed by a mapping of zw, by aa2 etc to zv, is equivalent to a single mapping zz–>zv by the transformatn with coefficients aa3,bb3,cc3,dd3, such that, as 2*2 complex matrices:
[ aa3, bb3 ] [ aa2, bb2 ] [ aa1, bb1 ]
[ ] = [ ] * [ ]
[ cc3, dd3 ] [ cc2, dd2 ] [ cc1, dd1 ] .
Note that the determinant of these matrices is always +1. Given a cartesian 3-vector representation of a point on the Riemann unit sphere, return the stereographically equivalent complex number.
- Parameters
-
[in] | v | cartesian 3-vector representation of point on Riemann sphere |
[out] | z | complex point stereographically equivalent to v |
[out] | infz | logical indicator for z being the point at infinity |
- Author
- R. J. Purser
Definition at line 2026 of file pmat4.f90.