
atan - the inverse tangens

Calling sequence:
atan(x)
atan(x,y)

Parameter:
x  --   expression
y  --   expression

Overloading:

all

Summary:

The call atan(x) represents the inverse tangens of the expression x. If the
argument x is of type DOM_FLOAT then the kernel function atan will be used
to compute the inverse tangens of x.

The two-argument function atan(x,y) computes the principal value of the
argument of the complex number x+I*y, thus -PI < atan(x,y) <= PI.

>>  atan(1.5);

     0.9827937232

>>  atan(2,3);

      atan(3/2)

>>  atan(1,infinity);

      PI
      --
      2

