RangeStdev - script and chart function

RangeStdev() finds the standard deviation of a range of numbers.

Syntax:  

RangeStdev(first_expr[, Expression])

Return data type: numeric

Arguments:  

The arguments of this function may contain inter-record functions which in themselves return a list of values.

Argument Description
first_expr The expression or field containing the data to be measured.
Expression Optional expressions or fields containing the range of data to be measured.

Limitations:  

If no numeric value is found, NULL is returned.

Examples and results:  

Examples Results
RangeStdev (1,2,4)

Returns 1.5275252316519

RangeStdev (null( ))

Returns NULL

RangeStdev (above(SalesValue),0,3))

Returns a sliding standard of the range of three values returned from the above() function calculated on the current row and the two rows above the current row.

Data used in example:

CustID RangeStdev(SalesValue, 0,3))
1-20

-,43.841, 34.192, 18.771, 20.953, 41.138, 47.655, 36.116, 32.716, 25.325,

38,000, 27.737, 35.553, 33.650, 42.532, 33.858, 32.146, 25.239, 35.595

SalesTable:

LOAD recno() as CustID, * inline [

SalesValue

101

163

126

139

167

86

83

22

32

70

108

124

176

113

95

32

42

92

61

21

] ;