Computes the variance among all values in a column using the sample statistical method. Input column can be of Integer or Decimal. If no numeric values are detected in the input column, the function returns |
The variance of a set of values attempts to measure the spread in values around the mean. A variance of zero means that all values are the same, and a small variance means that the values are closely bunched together. A high value for variance indicates that the numbers are spread out widely. Variance is always a positive value.
If a row contains a missing or null value, it is not factored into the calculation.
NOTE: This function applies to a sample of the entire population. More information is below. |
In the following computation, the sample method computes variances with N - 1 as the divisor.
Var(X) = [Sum ((X - mean(X))^{2})] / (Count(X) - 1)
The square root of variance is standard deviation, which is used to measure variance under the assumption of a bell curve distribution. See STDEV Function.
For a version of this function computed over a rolling window of rows, see ROLLINGVAR Function.
varsamp(myRating) |
Output: Returns the variance of the group of values from the myRating
column using the sample method of calculation.
varsamp(col_ref) [group:group_col_ref] [limit:limit_count] |
Argument | Required? | Data Type | Description |
---|---|---|---|
function_col_ref | Y | string | Name of column to which to apply the function |
For more information on the group
and limit
parameters, see Pivot Transform.
Name of the column whose values you wish to use in the calculation. Column must be a numeric (Integer or Decimal) type.
Required? | Data Type | Example Value |
---|---|---|
Yes | String (column reference) | myValues |