F105: Rotate a Three-Dimensional Polar Coordinate System

Author(s): M. Regler Library: MATHLIB
Submitter: Submitted: 01.03.1968
Language: Fortran Revised: 27.11.1984

POLROT calculates the values of tex2html_wrap_inline73 and tex2html_wrap_inline75 of the coordinate system tex2html_wrap_inline77 , obtained by rotation of the 3-dimensional polar coordinate system tex2html_wrap_inline79 about any axis tex2html_wrap_inline81 .

Structure:

SUBROUTINE subprogram
User Entry Names: POLROT

Usage:

    CALL POLROT(THETA,PHI,THPRIM,PHPRIM,THAX,PHAX,ROTANG)
THETA
(REAL) Angle tex2html_wrap_inline83 in the old system tex2html_wrap_inline85 .
PHI
(REAL) Angle tex2html_wrap_inline87 in the old system tex2html_wrap_inline89 .
THPRIM
(REAL) Angle tex2html_wrap_inline91 in the new system tex2html_wrap_inline93 .
PHPRIM
(REAL) Angle tex2html_wrap_inline95 in the new system tex2html_wrap_inline97 .
THAX,PHAX
(REAL) Angles defining the axis of rotation in the old system tex2html_wrap_inline99 .
ROTANG
(REAL) Angle in the old system through which the system is rotated.
The subroutine calculates from THETA and PHI the new values THPRIM and PHPRIM in a coordinate system obtained by rotating the old system through an angle ROTANG about an axis defined by THAX and PHAX in the old system.

Method:

THETA and PHI are converted to a unit vector in Cartesian coordinates; THAX, PHAX and ROTANG are converted to a tensor, which is used to obtain a vector in the new system of axes giving THPRIM and PHPRIM.

Notes:

If THPRIM is very small, PHPRIM is badly defined.
tex2html_wrap_inline101

Michel Goossens Wed Jun 5 04:49:08 METDST 1996