sdev (replaces TSdev)

The sdev function returns the standard deviation of a 1-dimensional array, CImage, or list of numbers. The array and list parameters must contain a mixture of numbers and strings that can be converted to numbers. This function is similar to the CStat:Sdev method but does not require calling new_stats() beforehand to create a CStats object.

Syntax

nStdDev = sdev( Data )

bullet.gif    Data is a 1-dimensional array, list of numbers, or a CImage object.

bullet.gif    n1, n2, n3, ... are numbers or string values that can be converted to numbers.

bullet.gif    nStdDev is the standard deviation of the values.

Remarks

Except for the CImage class, the members of Data are interpreted as numbers with pixel type "double". The CImage class supports values ranging from byte to double plus other pixel types.

Examples

The following script returns the standard deviation of a table containing 1 million random numbers.

t = random( 1000000 )

-- create a table of numbers

sd = sdev( t )

-- find the standard deviation

Printf("Sdev= %lg\n", sd )

-- list the result

  

The next script returns the standard deviation for pixels inside a rectangle at the corner of a CImage.

V = AttachView( "CImageView" )

-- attach the topmost image window

Assert( V and V:Count() > 0 )

-- make sure an image window is on top

R = new_rect( 1, 20, 1, 40 )

-- rectangle for corner of image

sd = sdev( V:GetImage(), R )

-- use the current image in the CImageView

Printf("Sdev= %lg\n", sd )

-- list the result

  

The next example computes the standard deviation of a list of numbers:

s = sdev( 5, 6, -2, 5.4 }

-- find the standard deviation

Printf("SDev = %lg\n", m )

-- result: SDev = 3.12

Related Topics

Table and Array Functions, mean, sdevn, sdevxn, CImageView Class


Mira Pro x64 Script User's Guide, Copyright Ⓒ 2023 Mirametrics, Inc. All Rights Reserved.