STDEV

Purpose:

Calculates the sample standard deviation of a series.

Syntax:

STDEV(series, first, points)

series

-

Optional. Any series or expression resulting in a series. Defaults to the current Window.

first

-

Optional. An integer, the first point to include in the calculation of the standard deviation. Defaults to 1.

points

-

Optional. An integer, the number of points to include in the standard deviation calculation. Defaults to the number of points from first to the end of the series.

Returns:

A real.

Example:

stdev(gsin(100,0.01), 5, 20)

 

returns the standard deviation value 0.2403611.

Example:

stdev(W3, 5, 10)

 

returns the standard deviation of 10 points of the series in Window 3 starting with the 5th point.

Remarks:

STDEV computes the sample standard deviation defined as:

 

image\std01.gif

 

where the arithmetic mean is defined as:

 

image\std02.gif

 

STATS provides both STDEV and MEAN.

 

NaN values are ignored.

 

COLSTDEV can be used to determine the standard deviations of each column in a table.

 

See STD to calculate the population standard deviation.

See Also:

COLSTDEV

KURTOSIS

MEAN

MOVSTD

RMS

ROWSTDEV

SKEW

STATS

STATSUM

STD

STDERR