stats::stdev

Standard deviation of a data sample

Use only in the MuPAD Notebook Interface.

This functionality does not run in MATLAB.

Syntax

stats::stdev(x1, x2, …, <Sample | Population>)
stats::stdev([x1, x2, …], <Sample | Population>)
stats::stdev(s, <c>, <Sample | Population>)

Description

stats::stdev( x1, x2, ..., xn) returns the standard deviation

,

where is the arithmetic mean of the data xi.

stats::stdev( x1, x2, ..., xn, Population) returns

.

The standard deviation is the square root of the variance.

The column index c is optional, if the data are given by a stats::sample object containing only one non-string column. Cf. Example 3.

External statistical data stored in an ASCII file can be imported into a MuPAD® session via import::readdata. In particular, see Example 1 of the corresponding help page.

Examples

Example 1

We calculate the standard deviation of three values:

stats::stdev(2, 3, 5)

Alternatively, the data may be passed as a list:

stats::stdev([2, 3, 5])

Example 2

We create a sample:

stats::sample([[a1, b1, c1], [a2, b2, c2]])
a1  b1  c1
a2  b2  c2

The standard deviation of the second column is:

expand(stats::stdev(%, 2))

Example 3

We create a sample consisting of one string column and one non-string column:

stats::sample([["1996", 1242], ["1997", 1353], ["1998", 1142]])
"1996"  1242
"1997"  1353
"1998"  1142

We compute the standard deviation of the second column. In this case this column does not have to be specified, since it is the only non-string column:

float(stats::stdev(%))

We repeat the computation with the option Population:

float(stats::stdev(%2, Population))

Parameters

x1, x2, …

The statistical data: arithmetical expressions

s

A sample of domain type stats::sample

c

An integer representing a column index of the sample s. This column provides the data x1, x2 etc.

Options

Population, Sample

With Sample, the data are regarded as a "sample", not as a full population. The default is Sample.

Return Values

Arithmetical expression.

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