stats

stats (replaces TStats)

The stats function computes the mean, standard deviation, and other basic statistics for numeric data and returns them in an indexed table. The parameters may be a CImage, CMatrix, or CArray object, a 1-dimensional array, or a list of numbers. The parameters must contain numbers or strings that can be converted to numbers.

This function returns an array of values like [1]=value, whereas statstr returns a table with ["name"]=value pairs.

Syntax

tbl = stats( CImage )

tbl = stats( CImage, CRect )

tbl = stats( CMatrix )

tbl = stats( CArray )

tbl = stats( table )

tbl = stats( num1, num2, num3, ... )

The returned value tbl is an indexed table containing the following 8 values:

tbl[1] is the mean value returned in table index 1.

tbl[2] is the median value returned in table index 2.

tbl[3] is the standard deviation returned in table index 3.

tbl[4] is the minimum value returned in table index 4.

tbl[5] is the maximum value returned in table index 5.

tbl[6] is the statistical skewness returned in table index 6.

tbl[7] is the statistical kurtosis returned in table index 7.

tbl[8] is the number of values in the sample returned in table index 8.

On success, tbl is returned.

On failure, nil is returned.

Example

Suppose a CImage I exists. The following script returns the mean and standard deviation of 600 pixels in the corner of the image:

tbl = stats( I, new_rect(10,30,15,35) )	-- computes values inside the CRect
Printf("mean=%lg +/- %lg\n", tbl[1], tbl[3] )	-- list the result

Syntax

Example

Related Topics