abs

{ $abs: <number> }

Returns the absolute value of a number.

For example:

{ $abs: -3 }

acos

{ $acos: <expression> }

Returns the inverse cosine (arc cosine) of a value.

For example:

{ $acos : "$col" };

acosh

{ $acosh: <expression> }

Returns the inverse hyperbolic cosine (hyperbolic arc cosine) of a value.

For example:

{ $acosh: "$col" }

add

{ $add: [ <expression1>, <expression2>, ... ] }

Adds numbers together or adds numbers and a date. If one of the arguments is a date, $add treats the other arguments as milliseconds to add to the date.

For example:

{ $add: [ 1, 2 ] }

asin

{ $asin: <expression> }

Returns the inverse sine (arc sine) of a value.

For example:

{ $asin: "$col" }

asinh

{ $asinh: <expression> }

Returns the inverse hyperbolic sine (hyperbolic arc sine) of a value.

For example:

{ $asinh: "$col" };

atan

{ $atan: <expression> }

Returns the inverse tangent (arc tangent) of a value.

For example:

{ $atan: "$col" }

atan2

{ $atan2: [ <expression 1>, <expression 2> ] }

Returns the inverse tangent (arc tangent) of y / x, where y and x are the first and second values passed to the expression respectively.

For example:

{ $atan2 : [ "$side_b", "$side_a" ] }

ceil

{ $ceil: <number> }

Returns the smallest integer greater than or equal to the specified number.

For example:

{ $ceil: 7.80" }

cos

{ $cos: <expression> }

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

For example:

{ $cos: "$value" }

divide

{ $divide: [ <expression1>, <expression2> ] }

Divides one number by another and returns the result.

For example:

{ $divide: [ 8, 8 ] }

exp

{ $exp: <exponent> }

Raises Euler’s number (i.e. e ) to the specified exponent and returns the result.

For example:

{ $exp: 0 }

floor

{ $floor: <number> }

Returns the largest integer less than or equal to the specified number.

For example:

{ $floor: 9.25 }

ln

{ $ln: <number> }

Calculates the natural logarithm ln (i.e loge) of a number and returns the result as a double.

For example:

{ $ln: 10 }

log

{ $log: [ <number>, <base> ] }

Calculates the log of a number in the specified base and returns the result as a double.

For example:

{ $log: [ 100, 10 ] }

log10

{ $log10: <number> }

Calculates the log base 10 of a number and returns the result as a double.

For example:

{ $log10: 100 }

mod

{ $mod: [ <expression1>, <expression2> ] }

Divides one number by another and returns the remainder.

For example:

{ $mod: [ 15, 4 ] }

multiply

{ $multiply: [ <expression1>, <expression2>, ... ] }

Multiplies numbers together and returns the result.

For example:

{ $multiply: [ 10, 0.1 ] }

pow

{ $pow: [ <number>, <exponent> ] }

Raises a number to the specified exponent and returns the result.

For example:

{ $pow: [ 5, 2 ] }

range

{ $range: [ <start>, <end>, <non-zero step> ] }

Returns an array whose elements are a generated sequence of numbers. $range generates the sequence from the specified starting number by successively incrementing the starting number by the specified step value up to but not including the end point.

For example:

{ $range: [ 0, 10, 2 ] }

round

{ $round : [ <number>, <place> ] }

$round rounds a number to to a whole integer or to a specified decimal place.

For example:

{ $round: [ 2.22, 1 ] }

sin

{ $sin: <expression> }

Returns the sine of a value that is measured in radians.

For example:

{ $sin: "$col" };

sqrt

{ $sqrt: <number> }

Calculates the square root of a positive number and returns the result as a double.

For example:

{ $sqrt: 25 }

subtract

{ $subtract: [ <expression1>, <expression2> ] }

Subtracts two numbers to return the difference, or two dates to return the difference in milliseconds, or a date and a number in milliseconds to return the resulting date.

For example:

{ $subtract: [ 3, 2 ] }

tan

{ $tan: <expression> }

Returns the tangent of a value that is measured in radians.

For example:

{ $tan: "$col" }

trunc

{ $trunc : [ <number>, <place> ] }

$trunc truncates a number to a whole integer or to a specified decimal place.

For example:

{ $trunc: [ 1.56, 1 ] }