Database Manual / Reference / Query Language / Expressions

$cosh (expression operator)

$cosh

Returns the hyperbolic cosine of a value that is measured in radians.

$cosh has the following syntax:

{ $cosh: <expression> }

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

By default $cosh returns values as a double. $cosh can also return values as a 128-bit decimal if the <expression> resolves to a 128-bit decimal value.

For more information on expressions, see Expressions.

Behavior

null, NaN, and +/- Infinity

If the input argument resolves to a value of null or refers to a field that is missing, $cosh returns null. If the argument resolves to NaN, $cosh returns NaN. If the argument resolves to negative or positive Infinity, $cosh returns positive Infinity.

ExampleResults

{ $cosh: NaN }

NaN

{ $cosh: null }

null

{ $cosh: -Infinity }

Infinity

{ $cosh: Infinity }

Infinity

Example

The following trigonometry collection contains a document that stores an angle value measured in degrees:

db.trigonometry.insertOne(
   {
      "_id" : ObjectId( "5c50782193f833234ba90d85" ),
      "angle" : Decimal128( "53.1301023541559787031443874490659" )
   }
)

The following aggregation operation uses the $cosh expression to calculate the hyperbolic cosine of angle and adds it to the input document using the $addFields pipeline stage:

db.trigonometry.aggregate( [
   {
      $addFields : {
         "cosh_output" : { $cosh : { $degreesToRadians : "$angle" } }
      }
   }
] )

The $degreesToRadians expression converts the angle in degrees to radians.

Example output:

{
   "_id" : ObjectId("5c50782193f833234ba90d85"),
   "angle" : Decimal128("53.1301023541559787031443874490659"),
   "cosh_output" : Decimal128("1.461642741099671277595921778079396")
}

Because angle is stored as a 128-bit decimal, the $cosh output is also a 128-bit decimal.

The following trigonometry collection contains a document that stores an angle value measured in radians:

db.trigonometry.insertOne(
   {
      "_id" : ObjectId( "5c50782193f833234ba90d15" ),
      "angle" : Decimal128( "1.6301023541559787031443874490659" )
   }
)

The following aggregation operation uses the $cosh expression to calculate the hyperbolic cosine of angle and adds it to the input document using the $addFields pipeline stage:

db.trigonometry.aggregate( [
   {
      $addFields : {
         "cosh_output" : { $cosh : "$angle" }
      }
   }
] )

Example output:

{
   "_id" : ObjectId("5c50782193f833234ba90d15"),
   "angle" : Decimal128("1.6301023541559787031443874490659"),
   "cosh_output" : Decimal128("2.650153334504361016712328539738000")
}

Because angle is stored as a 128-bit decimal, the $cosh output is also a 128-bit decimal.