grid_tools  1.8.0
pmat4::setmobius Interface Reference

Private Member Functions

subroutine setmobius (xc0, xc1, xc2, aa, bb, cc, dd)
 Find the Mobius transformation complex coefficients, aa,bb,cc,dd, with aa*dd-bb*cc=1, for a standard (north-)polar stereographic transformation that takes cartesian point, xc0 to the north pole, xc1 to (lat=0,lon=0), xc2 to the south pole (=complex infinity). More...
 
subroutine zsetmobius (z0, infz0, z1, infz1, z2, infz2, aa, bb, cc, dd)
 Find the Mobius transformation complex coefficients, aa,bb,cc,dd, with aa*dd-bb*cc=1, that takes polar stereographic point, z0 to the north pole, z1 to (lat=0,lon=0), z2 to the south pole (=complex infinity). More...
 

Detailed Description

Definition at line 107 of file pmat4.f90.

Constructor & Destructor Documentation

◆ setmobius()

subroutine pmat4::setmobius::setmobius ( real(dp), dimension(3), intent(in)  xc0,
real(dp), dimension(3), intent(in)  xc1,
real(dp), dimension(3), intent(in)  xc2,
complex(dpc), intent(out)  aa,
complex(dpc), intent(out)  bb,
complex(dpc), intent(out)  cc,
complex(dpc), intent(out)  dd 
)
private

Find the Mobius transformation complex coefficients, aa,bb,cc,dd, with aa*dd-bb*cc=1, for a standard (north-)polar stereographic transformation that takes cartesian point, xc0 to the north pole, xc1 to (lat=0,lon=0), xc2 to the south pole (=complex infinity).

Parameters
[in]xc0cartesian point that will map to (0,0,1)
[in]xc1cartesian point that will map to (1,0,0)
[in]xc2cartesian point that will map to (0,0,-1)
[out]aaMobius transformation complex coefficient
[out]bbMobius transformation complex coefficient
[out]ccMobius transformation complex coefficient
[out]ddMobius transformation complex coefficient
Author
R. J. Purser

Definition at line 2123 of file pmat4.f90.

Member Function/Subroutine Documentation

◆ zsetmobius()

subroutine pmat4::setmobius::zsetmobius ( complex(dp), intent(in)  z0,
logical, intent(in)  infz0,
complex(dp), intent(in)  z1,
logical, intent(in)  infz1,
complex(dp), intent(in)  z2,
logical, intent(in)  infz2,
complex(dpc), intent(out)  aa,
complex(dpc), intent(out)  bb,
complex(dpc), intent(out)  cc,
complex(dpc), intent(out)  dd 
)
private

Find the Mobius transformation complex coefficients, aa,bb,cc,dd, with aa*dd-bb*cc=1, that takes polar stereographic point, z0 to the north pole, z1 to (lat=0,lon=0), z2 to the south pole (=complex infinity).

Should any one of z0,z1,z2 be itself the "point at infinity" its corresponding infz will be set "true" (and the z value itself not used). This routine is like setmobius, except the three fixed points defining the mapping are given in standard complex stereographic form, together with the logical codes "infzn" that are TRUE if that point is itself the projection pole (i.e., the South Pole for a north polar stereographic).

Parameters
[in]z0complex input point that will map to (0,0)
[in]infz0logical indicator that z0 is the point at infinity
[in]z1complex input point that will map to (1,0)
[in]infz1logical indicator that z1 is the point at infinity
[in]z2complex input point that will map to infinity
[in]infz2logical indicator that z2 is the point at infinity
[out]aaMobius transformation complex coefficient
[out]bbMobius transformation complex coefficient
[out]ccMobius transformation complex coefficient
[out]ddMobius transformation complex coefficient
Author
R. J. Purser

Definition at line 2206 of file pmat4.f90.


The documentation for this interface was generated from the following file: