variance_y() | variance_x()
Calculate the variance from a two-dimensional statistical aggregate for the dimension specified
Since 1.3.0
Calculate the variance from a two-dimensional statistical aggregate for the given dimension. For example, variance_y()
calculates the skewness for all the values of the y variable, independent of values of the x variable.
Samples
Section titled “Samples”Calculate the variance of a sample containing the integers from 0 to 100:
SELECT variance_y(stats_agg(data, data))FROM generate_series(0, 100) data;variance_y----------858.5Arguments
Section titled “Arguments”The syntax is:
variance_y( summary StatsSummary2D, [ method TEXT ]) RETURNS DOUBLE PRECISIONvariance_x( summary StatsSummary2D, [ method TEXT ]) RETURNS DOUBLE PRECISION| Name | Type | Default | Required | Description |
|---|---|---|---|---|
| summary | StatsSummary2D | - | ✔ | The statistical aggregate produced by a stats_agg call |
| method | TEXT | sample | - | The method used for calculating the standard deviation. The two options are population and sample, which can be abbreviated to pop or samp |
Returns
Section titled “Returns”| Column | Type | Description |
|---|---|---|
| variance | DOUBLE PRECISION | The variance of the values in the statistical aggregate |