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diff --git a/doc/man/libred_solar_elevation.3 b/doc/man/libred_solar_elevation.3 new file mode 100644 index 0000000..b87124a --- /dev/null +++ b/doc/man/libred_solar_elevation.3 @@ -0,0 +1,65 @@ +.TH LIBRED_SOLAR_ELEVATION 3 LIBRED +.SH NAME +libred_solar_elevation \- Calculate the Sun's apparent elevation +.SH SYNOPSIS +.nf +#include <libred.h> + +double \fBlibred_solar_elevation\fP(double \fIlatitude\fP, double \fIlongitude\fP); +.fi +.PP +Link with +.IR -lred . +.SH DESCRIPTION +.B libred_solar_elevation +calculates the Sun's elevation as apparent from a select geographical position. +Namely from +.I latitude +degrees north of GPS's equator and +.I longitude +degrees east of GPS's prime meridian. The function is only explicitly defined for +values between -90 and +90 for +.I latitude +and values between -180 and +180 for and +.IR longitude . +Other values may or may not work, not error is thrown if used. +.SH "RETURN VALUE" +Upon successful completion, the function sets +.B errno +to 0 and returns the Sun's current apparent elevation, measured in +degrees above the horizon. On failure, the function returns an +arbitrary value (happens to always be 0.0) and sets +.B errno +an a non-zero value. +.SH ERRORS +The function may fail for any reason specified for +.BR clock_gettime (3), +and set the value of +.B errno +to the same values. +.B errno +is always set to 0 on success. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.BR libred.h (0), +.BR libred (7), +.BR libred_check_timetravel (3), +.BR libred_init_colour (3) +.SH LICENSE +Copyright \(co 2016 Mattias Andrée +.br +License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. +.br +This is free software: you are free to change and redistribute it. +.br +There is NO WARRANTY, to the extent permitted by law. +.PP +Copying and distribution of this manual, with or without modification, +are permitted in any medium without royalty provided the copyright +notice and this notice are preserved. This file is offered as-is, +without any warranty. +.SH BUGS +Please report bugs to <https://github.com/maandree/libred/issues> +or to <maandree@member.fsf.org>. + |