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$cos (operador de expressão )

Definição

$cos

Retorna o cosseno de um valor medido em radianos.

$cos tem a seguinte sintaxe:

{ $cos: <expression> }

$cos takes any valid expression that resolves to a number. If the expression returns a value in degrees, use the $degreesToRadians operator to convert the result to radians.

By default $cos returns values as a double. $cos can 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`, `NaN` e `+/- Infinity`

If the argument resolves to a value of null or refers to a field that is missing, $cos returns null. If the argument resolves to NaN, $cos returns NaN. If the argument resolves to negative or positive infinity, $cos throws an error.

Exemplo

Resultados

{ $cos: NaN }

NaN

{ $cos: null }

null

{ $cos : Infinity}

{ $cos : -Infinity }

Lança uma mensagem de erro semelhante à seguinte saída formatada:

"errmsg" :
  "Failed to optimize pipeline :: caused by :: cannot
  apply $cos to -inf, value must in (-inf,inf)"

Exemplo

A collection trigonometry contém um documento que armazena a hipotenusa e um ângulo em um triângulo retângulo:

{
  "_id" : ObjectId("5c50782193f833234ba90d85"),
  "angle_a" : Decimal128("53.13010235415597870314438744090659"),
  "hypotenuse" : Decimal128("5")
}

The following aggregation operation uses the $cos expression to calculate the side adjacent to angle_a and add it to the input document using the $addFields pipeline stage.

db.trigonometry.aggregate([
  {
    $addFields : {
      "side_a" : {
        $multiply : [
          { $cos : {$degreesToRadians : "$angle_a"} },
          "$hypotenuse"
        ]
      }
    }
  }
])

A expressão $degreesToRadians converte o valor do grau de angle_a no valor equivalente em radianos.

O comando retorna a seguinte saída:

{
  "_id" : ObjectId("5c50782193f833234ba90d85"),
  "angle_a" : Decimal128("53.13010235415597870314438744090659"),
  "side_a" : Decimal128("2.999999999999999999999999999999999"),
  "hypotenuse" : Decimal128("5"),
}

Since angle_a and hypotenuse are stored as 128-bit decimals, the output of $cos is a 128-bit decimal.

A collection trigonometry contém um documento que armazena a hipotenusa e um ângulo em um triângulo retângulo:

{
  "_id" : ObjectId("5c50782193f833234ba90d85"),
  "angle_a" : Decimal128("0.9272952180016122324285124629224288"),
  "hypotenuse" : Decimal128("5")
}

The following aggregation operation uses the $cos expression to calculate the side adjacent to angle_a and add it to the input document using the $addFields pipeline stage.

db.trigonometry.aggregate([
  {
    $addFields : {
      "side_b" : {
        $multiply : [
          { $cos : "$angle_a" },
          "$hypotenuse"
        ]
      }
    }
  }
])

O comando retorna a seguinte saída:

{
  "_id" : ObjectId("5c50782193f833234ba90d85"),
  "angle_a" : Decimal128("0.9272952180016122324285124629224288"),
  "side_b" : Decimal128("3.000000000000000000000000000000000"),
  "hypotenuse" : Decimal128("5"),
}

Since angle_a and hypotenuse are stored as 128-bit decimals, the output of $cos is a 128-bit decimal.

Voltar

$convert

$cosh

$cos (operador de expressão )

Definição

Comportamento

null, NaN e +/- Infinity

Exemplo

`null`, `NaN` e `+/- Infinity`