sdevn

sdevn

The sdevn function returns the standard deviation of a general lua table that may contain a multi-dimensional array or a mixture of numbers, strings, named keys, and sub-tables. Only numeric values found in the table are used in the calculation. The related sdev function calculates the mean of a 1-dimensional array, CImage, or list of numbers. Since an array is a specific type of table that contains only numbers or sub-tables, this function can also be used for arrays.

Syntax

nStdDev = sdevn( tbl )

tbl is a general lua table.

nStdDev is the standard deviation of the values.

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 = sdevn( t )	-- find the standard deviation
Printf("Sdev= %lg\n", sd )	-- list the result

The next example computes the standard deviation of an ugly, complex table:

t = { 6, -2, 15, "a", {5,"b"}, c="5.4" }
sd = sdevn(t)	-- find the standard deviation
Printf("Sdev = %lg\n", sd )	-- result: Sdev = 6.97615 using 4 values

Syntax

Examples

Related Topics