| Navigation: Templates > Guide to all Templates > Additional Libraries and Templates > Statistics Library >====== VARIANCES (variance of a sample) ====== |    |
VARIANCES(dataset [,meanofset])
| VARIANCES | Returns the variance of a sample of a numeric set. |
| dataset | The label of a QUEUE with its first component field defined as a REAL. |
| meanofset | A numeric constant or variable representing the average of the data set's values (optional). |
VARIANCES computes the variance of a given sample data set. VARIANCEP computes the variance of a given population data set. The 'Sample' function call should be used only if the data set contains less than all of a population's values. Both functions operate on on the numeric set defined by all the entries in the first component of the designated QUEUE (dataset).
The optional parameter helps to optimize the function. If not provided, the value is computed internally by the function.
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
END
VarianceOfSet REAL
CODE
FREE(StatSetX) !free the QUEUE
CLEAR(STADAT:RECORD) !clear the record buffer
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
StatSetX:X = STADAT:X !load the QUEUE buffer
ADD(StatSetX) !add to the QUEUE
END
END
VarianceOfSet = VARIANCES(StatSetX) !call VARIANCES