Package dev.morphia.aggregation.expressions

Class WindowExpressions

  • public final class WindowExpressions
extends Object
    Provides window specific operations.
    Since:
    2.3

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static dev.morphia.aggregation.expressions.impls.Expression covariancePop​(dev.morphia.aggregation.expressions.impls.Expression first, dev.morphia.aggregation.expressions.impls.Expression second)
      Returns the population covariance of two numeric expressions that are evaluated using documents in the $setWindowFields stage window.
      static dev.morphia.aggregation.expressions.impls.Expression covarianceSamp​(dev.morphia.aggregation.expressions.impls.Expression first, dev.morphia.aggregation.expressions.impls.Expression second)
      Returns the sample covariance of two numeric expressions that are evaluated using documents in the $setWindowFields stage window.
      static dev.morphia.aggregation.expressions.impls.Expression denseRank()
      Returns the document position (known as the rank) relative to other documents in the $setWindowFields stage partition.
      static dev.morphia.aggregation.expressions.impls.CalculusExpression derivative​(dev.morphia.aggregation.expressions.impls.Expression input)
      Returns the average rate of change within the specified window.
      static dev.morphia.aggregation.expressions.impls.Expression documentNumber()
      Returns the position of a document (known as the document number) in the $setWindowFields stage partition.
      static dev.morphia.aggregation.expressions.impls.Expression expMovingAvg​(dev.morphia.aggregation.expressions.impls.Expression input, int n)
      Returns the exponential moving average of numeric expressions applied to documents in a partition defined in the $setWindowFields stage.
      static dev.morphia.aggregation.expressions.impls.CalculusExpression integral​(dev.morphia.aggregation.expressions.impls.Expression input)
      Returns the approximation of the area under a curve, which is calculated using the trapezoidal rule where each set of adjacent documents form a trapezoid using the:
      static dev.morphia.aggregation.expressions.impls.Expression linearFill​(dev.morphia.aggregation.expressions.impls.Expression fillValue)
      Fills null and missing fields in a window using linear interpolation based on surrounding field values.
      static dev.morphia.aggregation.expressions.impls.Expression locf​(dev.morphia.aggregation.expressions.impls.Expression fillValue)
      Last observation carried forward.
      static dev.morphia.aggregation.expressions.impls.Expression rank()
      Returns the document position (known as the rank) relative to other documents in the $setWindowFields stage partition.
      static dev.morphia.aggregation.expressions.impls.ShiftExpression shift​(dev.morphia.aggregation.expressions.impls.Expression output, long by, dev.morphia.aggregation.expressions.impls.Expression defaultValue)
      Returns the value from an expression applied to a document in a specified position relative to the current document in the $setWindowFields stage partition.
      static dev.morphia.aggregation.expressions.impls.Expression stdDevPop​(dev.morphia.aggregation.expressions.impls.Expression value, dev.morphia.aggregation.expressions.impls.Expression... additional)
      Returns the population standard deviation of the input values.
      static dev.morphia.aggregation.expressions.impls.Expression stdDevSamp​(dev.morphia.aggregation.expressions.impls.Expression value, dev.morphia.aggregation.expressions.impls.Expression... additional)
      Returns the sample standard deviation of the input values.

    • Method Detail

      • covariancePop

        public static dev.morphia.aggregation.expressions.impls.Expression covariancePop​(dev.morphia.aggregation.expressions.impls.Expression first,
                                                                                 dev.morphia.aggregation.expressions.impls.Expression second)
        Returns the population covariance of two numeric expressions that are evaluated using documents in the $setWindowFields stage window.

        $covariancePop is only available in the $setWindowFields stage.

        Parameters:
        first - the first expression to evaluate
        second - the second expression to evaluate
        Returns:
        the new expression
        Since:
        2.3
        See Also:
        Aggregation.setWindowFields(SetWindowFields)
        MongoDB documentation
        Aggregration Expression: $covariancePop
        Since server release
        5.0

      • covarianceSamp

        public static dev.morphia.aggregation.expressions.impls.Expression covarianceSamp​(dev.morphia.aggregation.expressions.impls.Expression first,
                                                                                  dev.morphia.aggregation.expressions.impls.Expression second)
        Returns the sample covariance of two numeric expressions that are evaluated using documents in the $setWindowFields stage window.

        $covarianceSamp is only available in the $setWindowFields stage.

        Parameters:
        first - the first expression to evaluate
        second - the second expression to evaluate
        Returns:
        the new expression
        Since:
        2.3
        See Also:
        Aggregation.setWindowFields(SetWindowFields)
        MongoDB documentation
        Aggregration Expression: $covarianceSamp
        Since server release
        5.0

      • denseRank

        public static dev.morphia.aggregation.expressions.impls.Expression denseRank()
        Returns the document position (known as the rank) relative to other documents in the $setWindowFields stage partition.
        Returns:
        the expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $denseRank
        Since server release
        5.0

      • derivative

        public static dev.morphia.aggregation.expressions.impls.CalculusExpression derivative​(dev.morphia.aggregation.expressions.impls.Expression input)
        Returns the average rate of change within the specified window.
        Parameters:
        input - Specifies the expression to evaluate. The expression must evaluate to a number.
        Returns:
        the new expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $derivative
        Since server release
        5.0

      • expMovingAvg

        public static dev.morphia.aggregation.expressions.impls.Expression expMovingAvg​(dev.morphia.aggregation.expressions.impls.Expression input,
                                                                                int n)
        Returns the exponential moving average of numeric expressions applied to documents in a partition defined in the $setWindowFields stage.

        $expMovingAvg is only available in the $setWindowFields stage.

        Parameters:
        input - Specifies the expression to evaluate. Non-numeric expressions are ignored.
        n - An integer that specifies the number of historical documents that have a significant mathematical weight in the exponential moving average calculation, with the most recent documents contributing the most weight.
        Returns:
        the new expression
        Since:
        2.3
        See Also:
        Aggregation.setWindowFields(SetWindowFields)
        MongoDB documentation
        Aggregration Expression: $expMovingAvg
        Since server release
        5.0

      • integral

        public static dev.morphia.aggregation.expressions.impls.CalculusExpression integral​(dev.morphia.aggregation.expressions.impls.Expression input)
        Returns the approximation of the area under a curve, which is calculated using the trapezoidal rule where each set of adjacent documents form a trapezoid using the:
        Parameters:
        input - Specifies the expression to evaluate. The expression must evaluate to a number.
        Returns:
        the new expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $integral
        Since server release
        5.0

      • linearFill

        public static dev.morphia.aggregation.expressions.impls.Expression linearFill​(dev.morphia.aggregation.expressions.impls.Expression fillValue)
        Fills null and missing fields in a window using linear interpolation based on surrounding field values.

        $linearFill is only available in the $setWindowFields stage.

        Parameters:
        fillValue - the expression to use when calculating fill values
        Returns:
        the fill expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $linearFill
        Since server release
        5.3

      • locf

        public static dev.morphia.aggregation.expressions.impls.Expression locf​(dev.morphia.aggregation.expressions.impls.Expression fillValue)
        Last observation carried forward. Set values for null and missing fields in a window to the last non-null value for the field.
        Parameters:
        fillValue - the expression to use when calculating fill values
        Returns:
        the fill expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $locf
        Since server release
        5.2

      • rank

        public static dev.morphia.aggregation.expressions.impls.Expression rank()
        Returns the document position (known as the rank) relative to other documents in the $setWindowFields stage partition.
        Returns:
        the new expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $rank
        Since server release
        5.0

      • shift

        public static dev.morphia.aggregation.expressions.impls.ShiftExpression shift​(dev.morphia.aggregation.expressions.impls.Expression output,
                                                                              long by,
                                                                              dev.morphia.aggregation.expressions.impls.Expression defaultValue)
        Returns the value from an expression applied to a document in a specified position relative to the current document in the $setWindowFields stage partition.
        Parameters:
        output - Specifies an expression to evaluate and return in the output.
        by - Specifies an integer with a numeric document position relative to the current document in the output.
        defaultValue - Specifies an optional default expression to evaluate if the document position is outside of the implicit $setWindowFields stage window. The implicit window contains all the documents in the partition.
        Returns:
        the expression
        Since:
        2.3
        See Also:
        Aggregation.setWindowFields(SetWindowFields)
        MongoDB documentation
        Aggregration Expression: $shift
        Since server release
        5.0

      • stdDevPop

        public static dev.morphia.aggregation.expressions.impls.Expression stdDevPop​(dev.morphia.aggregation.expressions.impls.Expression value,
                                                                             dev.morphia.aggregation.expressions.impls.Expression... additional)
        Returns the population standard deviation of the input values.
        Parameters:
        value - the value
        additional - any subsequent expressions to include in the expression
        Returns:
        the new expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $stdDevPop

      • stdDevSamp

        public static dev.morphia.aggregation.expressions.impls.Expression stdDevSamp​(dev.morphia.aggregation.expressions.impls.Expression value,
                                                                              dev.morphia.aggregation.expressions.impls.Expression... additional)
        Returns the sample standard deviation of the input values.
        Parameters:
        value - the value
        additional - any subsequent expressions to include in the expression
        Returns:
        the new expression
        Since:
        2.3
        MongoDB documentation
        Aggregration Expression: $stdDevSamp