Reference material for VAR_POP
Computes the population variance of all non-NULL
numeric values produced by an expression. The population variance measures the average of the squared differences from the population mean, indicating how spread out the values are within the entire population. For information about the sample variance, which measures how spread out the values are within a sample, see VAR_SAMP.
Parameter | Description | Supported input types |
---|---|---|
<expression> | An expression producing numeric values for which to calculate the population variance. | REAL , DOUBLE PRECISION |
VAR_POP
returns a result of type DOUBLE PRECISION
.
NULL
input values, the result is NULL
.Inf
or NaN
value, the result will be NaN
.The following code creates an exams
table with a grade
column of type DOUBLE PRECISION
, and inserts five grade values into it:
The following code calculates the population variance of the grade values from the exams
table, rounds the result to three decimal places, and returns it as variance
:
Returns The previous code returns the following result:
variance (DOUBLE PRECISION) |
---|
0.274 |