Explain the Aggregate Function ' VARP' in Tableau with Example?

 In Tableau, the VARP function is an aggregate function used to calculate the population variance of a numeric field within a specified context or group. The population variance measures the dispersion or spread of data points around the mean in the entire population.

The syntax for the VARP function in Tableau is as follows:

VARP(expression)

where the expression is the field or calculation for which you want to calculate the population variance.

Here's an example to demonstrate how to use the VARP function in Tableau:

Suppose you have a dataset that contains information about the test scores of students in a school. You want to calculate the population variance of the scores to understand the variability in the entire student population.

1. Open Tableau and connect to your dataset.
2. Drag the "Score" field to the Columns shelf.
3. In the Marks card, change the aggregation of the "Score" field to "VarP" by clicking on the drop-down arrow next to the field and selecting "VarP." This applies the VARP function to the "Score" field and calculates the population variance of the scores.
4. Tableau will display the population variance value in the view.

The result will show you the measure of how the scores deviate from the mean in the entire population. Similar to the sample variance, a higher population variance indicates a greater spread or variability in the scores, while a lower variance indicates a more clustered or consistent set of scores.

The VARP function calculates the population variance without assuming that the data is a sample from a larger population. If you are working with a sample of data, you might consider using the VAR function instead, which provides an estimate of the variance based on the sample.

In summary, the VARP function in Tableau allows you to calculate the population variance of a dataset, providing insights into the variability and dispersion of data points around the mean in the entire population.