IRAF help page for package language, program mathfcns

Function    Return value		  Description
sin(x)		real			sine
cos(x)		real			cosine
tan(x)		real			tangent
atan2(x,y)	real			arc-tangent
exp(x)		real			e**x
log(x)		real			natural logarithm
log10(x)	real			common logarithm
frac(x)		real			fractional part
abs(x)		type of argument	absolute value
min(a,b,...)	type of min. arg	minimum of a list of values
max(a,b,...)	type of max. arg	maximum of a list of values
real(x)		real			convert to real
int(x)		integer			integer part

DESCRIPTION A number of mathematical functions are available under the CL. In general they return real values and may be used wherever a real expression is valid. The input arguments may be integer or real and may be mixed in cases where the function has more than one argument. Exceptions:

    abs(x) 	returns real or integer depending on its argument
    int(x)	returns an integer
    min,max	return a copy of the min/max operand, no type change

Note that the intrinsic functions int and real may be called to decode string valued arguments.

y = sin (x)
  = 180 / 3.1415927 * atan2 (x, y)
i = int (max (4.3, x, y, 2))
  = 1. - (sin(.5)**2 + cos(.5)**2)

BUGS An invalid argument list to a math function (e.g. log(-1)) will terminate a script.

strings,