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stats::stdev -- the standard deviation

Introduction

stats::stdev(data) returns the standard deviation of the data.

Call(s)

stats::stdev(x1, x2, .. <, Sample>)
stats::stdev([x1, x2, ..] <, Sample>)
stats::stdev(s <, c> <, Sample>)

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

Sample - with this option the given data are regarded as a ``sample'', not as a full population.

Returns

an arithmetical expression.

Related Functions

stats::a_quantil, stats::geometric, stats::harmonic, stats::mean, stats::median, stats::modal, stats::quadratic, stats::variance

Details

Example 1

We calculate the standard deviation of three values:

>> stats::stdev(2, 3, 5)
   
                                     1/2
                                   14
                                   -----
                                     3
      

Alternatively, the data may be passed as a list:

>> stats::stdev([2, 3, 5])
   
                                     1/2
                                   14
                                   -----
                                     3
      

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))
   
                         /   2             2 \1/2
                         | b1    b1 b2   b2  |
                         | --- - ----- + --- |
                         \  4      2      4  /
      

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(%))
   
                                86.17939945
      

We repeat the computation with the option Sample:

>> float(stats::stdev(%2, Sample))
   
                                105.5477775
      

Changes




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