$acos (aggregation)
$acosNew in version 4.2.
Returns the inverse cosine (arc cosine) of a value.
$acoshas the following syntax:{ $acos: <expression> } $acostakes any valid expression that resolves to a number between-1and1, e.g.-1 <= value <= 1.$acosreturns values in radians. Use$radiansToDegreesoperator to convert the output value from radians to degrees.By default
$acosreturns values as adouble.$acoscan also return values as a 128-bit decimal as long as the<expression>resolves to a 128-bit decimal value.For more information on expressions, see Expressions.
Behavior
If the argument resolves to a value of null or refers to a field
that is missing, $acos returns null. If the
argument resolves to NaN, $acos returns NaN.
If the argument resolves to a value outside the bounds of
[-1, 1] inclusive, $acos throws an error.
Example | Results | |||
|---|---|---|---|---|
{ $acos: NaN } | NaN | |||
{ $acos: null } | null | |||
or
| Throws an error message resembling the following formatted output: |