$atanRetorna a tangente inversa (tangente arco) de um valor.
$atantem a seguinte sintaxe:{ $atan: <expression> } $atantakes any valid expression that resolves to a number.$atanreturns values in radians. Use$radiansToDegreesoperator to convert the output value from radians to degrees.By default
$atanreturns values as adouble.$atancan also return values as a 128-bit decimal as long as the<expression>resolves to a 128-bit decimal value.Para mais informações sobre expressões, consulte Expressões.
Comportamento
null e a NaN
If the argument resolves to a value of null or refers to a field that is missing, $atan returns null. If the argument resolves to NaN, $tan returns NaN.
Exemplo | Resultados |
|---|---|
|
|
|
|
Exemplo
A coleção trigonometry contém um documento que armazena três lados de um triângulo retângulo:
{ "_id" : ObjectId("5c50782193f833234ba90d85"), "side_a" : Decimal128("3"), "side_b" : Decimal128("4"), "hypotenuse" : Decimal128("5") }
The following aggregation operation uses the $atan expression to calculate the angle adjacent to side_a and add it to the input document using the $addFields pipeline stage.
db.trigonometry.aggregate([ { $addFields : { "angle_a" : { $radiansToDegrees : { $atan : { $divide : [ "$side_b", "$side_a" ] } } } } } ])
The $radiansToDegrees expression converts the radian value returned by $atan to the equivalent value in degrees.
O comando retorna a seguinte saída:
{ "_id" : ObjectId("5c50782193f833234ba90d85"), "side_a" : Decimal128("3"), "side_b" : Decimal128("4"), "hypotenuse" : Decimal128("5"), "angle_a" : Decimal128("53.13010235415597870314438744090658") }
Since side_b and side_a are stored as 128-bit decimals, the output of $atan is a 128-bit decimal.
A coleção trigonometry contém um documento que armazena três lados de um triângulo retângulo:
{ "_id" : ObjectId("5c50782193f833234ba90d85"), "side_a" : Decimal128("3"), "side_b" : Decimal128("4"), "hypotenuse" : Decimal128("5") }
The following aggregation operation uses the $atan expression to calculate the angle adjacent to side_a and add it to the input document using the $addFields pipeline stage.
db.trigonometry.aggregate([ { $addFields : { "angle_a" : { $atan : { $divide : [ "$side_b", "$side_a" ] } } } } ])
O comando retorna a seguinte saída:
{ "_id" : ObjectId("5c50782193f833234ba90d85"), "side_a" : Decimal128("3"), "side_b" : Decimal128("4"), "hypotenuse" : Decimal128("5"), "angle_a" : Decimal128("0.9272952180016122324285124629224287") }
Since side_b and side_a are stored as 128-bit decimals, the output of $atan is a 128-bit decimal.