stddev() / stddev_y() / stddev_x()

stddev(summary StatsSummary1D, method TEXT) RETURNS BIGINT
stddev_y(summary StatsSummary2D, method TEXT) RETURNS BIGINT
stddev_x(summary StatsSummary2D, method TEXT) RETURNS BIGINT

Get the standard deviation of the values contained in a statistical aggregate. In a two-dimensional stats_agg use the _y/ _x form to access the stddev of the dependent and independent variables.

The method determines whether you calculate a 'population' or 'sample' standard deviation. These values may be provided as their full names or may be abbreviated 'pop' or 'samp'. These are the only four accepted values for the method argument. The default is 'sample'.

For more information about statistical aggregate functions, see the hyperfunctions documentation.

Required arguments

NameTypeDescription
summaryStatsSummary1D/StatsSummary2DThe already constructed data structure from a previous stats_agg call

Optional Arguments

NameTypeDescription
methodTEXTThe method for the calculation 'population' or 'sample' (default)

Returns

ColumnTypeDescription
stddev/stddev_y/stddev_xDOUBLE PRECISIONThe standard deviation of the values in the statistical aggregate

Sample usage

SELECT stddev_y(stats_agg(data, data))
FROM generate_series(0, 100) data;
stddev_y 
----------
  29.3002

Found an issue on this page?

Report an issue!

Related Content