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ssxy_sum_of_squares_for_x_and_y_.htm
Navigation:  Templates > Guide to all Templates > Additional Libraries and Templates > Statistics Library >====== SSXY (sum of squares for x and y) ====== Previous pageReturn to chapter overviewNext page

SSXY(dataset [,meanX] [,meanY])

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SSXY Returns the sum of the products of the differences between each data point and its associated (either X or Y) mean value.
dataset The label of a QUEUE with its first two component fields defined as REAL. The first component contains the set of X values and the second component contains the set of Y values.
meanX A numeric constant or variable containing the average of the X values (optional).
meanY A numeric constant or variable containing the average of the Y values (optional).

SSXY computes the sum of the products of the differences between each data point and its associated (either X or Y) mean value. The function operates on the numeric sets defined by all the entries in the first two components of the designated QUEUE (dataset). The computation is a significant factor in linear regression formulas.

The optional parameters help to optimize the function. If not provided, the value(s) will be computed internally by the function.

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The passed data set does not have to be sorted. The function copies the passed set. The passed data set is unchanged.

Return DataType:    REAL

Example:

StatSetXY QUEUE,PRE()

X          REAL

Y          REAL

         END

SumOfSquares   REAL

CODE

STADAT:Id = STA:Id                 !prime the record buffer

STADAT:ItemNumber = 1

SET(STADAT:KeyIdItemNumber,STADAT:KeyIdItemNumber !position file pointer

LOOP                               !load the QUEUE

  NEXT(StatisticsData)             !read next record

  IF ERRORCODE() OR STADAT:Id NOT = STA:Id

    BREAK

  ELSE

    StatSetXY:X = STADAT:X         !load the QUEUE buffer

    StatSetXY:Y = STADAT:Y         !load the QUEUE buffer

    ADD(StatSetXY)                 !add to the QUEUE

  END

END

SumOfSquares = SSXY(StatSetXY)     !call SSXY

ssxy_sum_of_squares_for_x_and_y_.htm.txt · Last modified: 2021/04/15 15:57 (external edit)