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calc/help/atan2
2017-05-21 15:38:25 -07:00

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NAME
atan2 - angle to point
SYNOPSIS
atan2(y, x, [,acc])
TYPES
y real
x real
acc real
return real
DESCRIPTION
Return the angle which is determined by the point (x,y). This
function computes the arctangent of y/x in the range [-pi, pi].
The value acc specifies the accuracy of the result. By default, acc
is epsilon().
Note that by convention, y is the first argument.
To conform to the 4.3BSD ANSI/IEEE 754-1985 math lib, atan2(0,0) is
defined to return 0.
EXAMPLE
> print atan2(0,0), atan2(1,sqrt(3)), atan2(17,53,1e-100)
0 ~.52359877559829887307 ~.31038740713235146535
LIMITS
acc > 0
LIBRARY
NUMBER *qatan2(NUMBER *y, *x, *acc)
SEE ALSO
acos, asin, atan, cos, epsilon, sin, tan