euler {astrolibR} | R Documentation |
Transform between Galactic, celestial, and ecliptic coordinates
euler(ai, bi, select, fk4, radian)
ai |
longitude, in degrees unless radian=TRUE is set, scalar or vector |
bi |
latitude, degrees unless radian=TRUE is set, scalar or vector |
select |
integer (1-6) specifying type of coordinate transformation: 1 = RA-Dec (J2000) to Galactic; 2 = Galactic to RA-Dec; 3 = RA-Dec (J2000) to Ecliptic; 4 = Ecliptic to RA-Dec; 5 = Ecliptic to Galactic; 6 = Galactic to Ecliptic |
fk4 |
set to TRUE if input and output celestial and equatorial coordinates are given in equinox B1950 (default = FALSE) |
radian |
set to TRUE in all input and output angles are in radians rather than degrees (default = FALSE) |
J2000 coordinate conversions are based on sec. 1.2 of Perryman (1997).
Related functions are provided in CRAN packages moonsun and sphereplot.
ao |
longitude, in degrees |
bo |
latitude, in degrees |
Written by W. Landsman, February 1987; adapted from Fortran by Daryl Yentis NRL
R adaptation by Arnab Chakraborty (June 2013)
Perryman, M. (editor) 1997, The Hipparcos and Tycho Catalogues, Vol. 1, ESA SP-1200. http://www.rssd.esa.int/SA/HIPPARCOS/docs/vol1_all.pdf
# Input: RA and dec of Cyg X-1 # Output: Galactic long and lat = (71.334990, 3.0668335) euler(299.590315, 35.201604, 1)