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stddev

Calculates the sample standard deviation.

Prototype

	function stddev (
		data  : numeric   
	)

	return_val [1] :  float or double

Arguments

data

A numeric array of any dimensionality.

Return value

The return value will be a scalar of type double if data is double, and a scalar of type float otherwise.

Description

This function returns the sample standard deviation of the input data, regardless of dimensionality. Missing values (data@_FillValue) are ignored. To determine the number of data points used to calculate the standard deviation, use:

   N = num(.not.ismissing(data))

Technically, this function calculates the population standard deviation.

See Also

dim_stddev, avg, stat_trim

Examples

Example 1

The following calculates the sample standard deviation of 5 values.

  f = (/ 7, 9, -2, -8, 2/)
  std_f = stddev(f)
  print(std_f)

Variable: std_f
Type: float
Total Size: 4 bytes
            1 values
Number of Dimensions: 1
Dimensions and sizes:   [1]
Coordinates: 
(0)     6.8775

Example 2

The following calculates the sample standard deviation of a (3,5,10) array, f.

  f = onedtond(ispan(1, 150, 1), (/3, 5, 10/))
  stddev_f = stddev(f)
  print(stddev_f)

Variable: stddev_f
Type: float
Total Size: 4 bytes
            1 values
Number of Dimensions: 1
Dimensions and sizes:   [1]
Coordinates: 
(0)     43.44537