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atan(+Number, -Result)
-Result is atan(+Number)
Evaluates the trigonometric function atan(Number) and unifies the resulting
value with Result.
- Number
- A number.
- Result
- Output: float or breal.
Description
Evaluates the trigonometric function atan(Number) and unifies the resulting
value with Result.
This predicate can be used as a function in arithmetic expressions.
In coroutining mode, if Number is uninstantiated, the call to atan/2 is
delayed until this variable is instantiated.
Modes and Determinism
Exceptions
- (4) instantiation fault
- Number is not instantiated (non-coroutining mode only).
- (24) number expected
- Number is not of a numeric type.
Examples
Result is atan(0.0). % gives Result = 0.0
Result is atan(1.0). % gives Result = 0.785398
Result is atan(-8). % gives Result = -1.44644
See Also
is / 2