forums

Use these forums to ask questions and discuss Tableau.

Calculating Percentiles?

Posted June 10th, 2008 by Dan Cole
in Calculations

Can tableau calculate the value that represents the x percentile of a data set (similar to the excel Percentile() function)?

I currently am creating a line graph using Running Sum Of Total of Count with a 2nd calculation of Percent of Total to create charts, then exporting the data to access and then looking for the datapoint closest to the percentile that I'm looking for and then creating a report from the access database. This would be much easier if tableau could calculate this natively.

Dan Cole
danc@carilion.com

Add new comment

Comments

On June 11th, 2008 Erin Easter said:

Hi Dan,

This may be what you are asking to do but you can add reference lines that mark a specific location or region on the axis. For example, you can add a reference line at the 90th and 95th percentiles. Then you can quickly see the data points that lie in those regions on the axis.

Add a reference line by right-clicking the axis in your view and selecting Add Reference Line. In the subsequent dialog box, specify the line type to be a computed percentile and then specify the percentage. when finished, click OK.

Does that help?

reply
On June 17th, 2008 Dan Cole said:

It helps visually, but I was hoping to be able to show the resulting amount as values not necessarily graphically, or if graphically, just the points that represent specific percentiles (25, 50, 75, etc) and not every point in between.

I go through my MSAccess step to sift through all the points of data from the data export function to just get the percentiles/quartiles that I need.

I'd like to think that others analyzing process data would like to see how, for example, the 50th%'ile changed over time.

Dan

reply
On August 28th, 2008 HealthMaps said:

It would be very, very useful to see how percentiles change over time. This is really a poor man's quantile regression, or at least could be a very effective picture of something similar.

Seems Tableau needs percentile and median functions that could be added as default aggregations as well as functions for making new variables.

Seems any function that is in Excel should be in Tableau.

reply
Syndicate content Subscribe to the comments on "Calculating Percentiles?"