5 Replies Latest reply on Aug 9, 2018 7:41 AM by Joseph Ward

# Plotting pre-calculated confidence bands

Hi all,

I am trying to plot rates over time by gender (male, female and all). I would like to include 95% confidence intervals for each series in the plot. As these are rates (and our real data are based on small numbers of events), I have calculated the 95% confidence intervals from a Poisson distribution. Calculating the confidence intervals is fine, but I am not sure how to plot them.

I have found resources to plot intervals for one series:

http://www.vizwiz.com/2014/02/tableau-tip-make-great-looking-band.html

http://www.vizwiz.com/2015/10/tableau-tip-tuesday-create-great.html

but I'm at a loss when there are multiple series on a chart.

I have attached a sample workbook based on dummy data. I've also attached an image below showing what I'd like to get to (produced in R).

Any help would be greatly appreciated.

Cheers

Tim

• ###### 1. Re: Plotting pre-calculated confidence bands

Timothy,

This isn't great, but maybe it can give an idea.

I think it all is an issue with sorting the order of the

unstacked area charts. I couldn't properly sort

using Measure Names, so I pivoted the Ucl and Lcl

into one column so that I could use Pivot Field Name

in a combined field with Gender.

Then, I manually ordered the fields from lowest to highest

and colored all the Lcls to background.

One of the problems is that I had to set the Opacity to 100%,

so overlapped parts will get cut off.

• ###### 2. Re: Plotting pre-calculated confidence bands

Thanks for the reply, I appreciate it. One of the aims of presenting the confidence intervals is to see when they overlap, so I'll have to keep hunting to see how to incorporate the option of overlapping intervals.

• ###### 3. Re: Plotting pre-calculated confidence bands

Hi Tim

I have exactly the same problem! IM trying to plot mortality rates over time with 95% confidence intervals calculated using poisson distribution. I also need to show when they overlap, so i don't think an area chart will help - did you get anywhere?

Thanks

Joe

• ###### 4. Re: Plotting pre-calculated confidence bands

Hi Tim

Did you manage to find a solution to the confidence interval problem?

Thanks

Joe

• ###### 5. Re: Plotting pre-calculated confidence bands

Hi Tim

Did you manage to find a solution to the confidence interval problem?

Thanks

Joe