topic Re: Data Expression for Pie Chart in Dashboard Fails in ArcGIS Dashboards Questions

Data Expression for Pie Chart in Dashboard Fails

Anonymous User — Tue, 07 Sep 2021 17:32:20 GMT

I'm creating a dashboard for road signs. Each sign has the installation year (4 digit integer). (The field name is "Installation"). I want to show a pie chart that shows if signs are <10 years old, 11-20 years old, or >20 years old.

This is my first time trying to do this in a data expression, and I can't get the correct results. It says all the signs are 11-20 years old. I also realized the "ageyrs" variable says it's Nan. So something somewhere isn't calculating right. Can anyone spot what I need to fix in my code?

@XanderBakker

Re: Data Expression for Pie Chart in Dashboard Fails

XanderBakker — Tue, 07 Sep 2021 17:56:59 GMT

Hi @Anonymous User ,

One of the issues in your code is that you using "fs" as if it contains the installation date. In this case "fs" is a featureset and you will loop through the features, read out the installation date and and fill the output "Dict" with the values calculated. Have a look at the code below:

If you just want to return a count per age class you could also create an intermediate dictionary for each class value and update the count.

Re: Data Expression for Pie Chart in Dashboard Fails

Anonymous User — Wed, 08 Sep 2021 10:51:25 GMT

That definitely helps and makes more sense. However it still isn't calculating the Sign Age correctly. Therefore all the signs show up as 11-20yrs old which isn't correct. Does it matter that the the Installation field is an integer field?

Re: Data Expression for Pie Chart in Dashboard Fails

Anonymous User — Wed, 08 Sep 2021 10:56:07 GMT

I made a few minor tweaks and got it to work! Thank you so much for you help! I was searching for a quite some time yesterday trying to figure this out. Below is the updated code.

Re: Data Expression for Pie Chart in Dashboard Fails

XanderBakker — Wed, 08 Sep 2021 13:17:34 GMT

Hi @Anonymous User ,

I'm glad it works and as you noticed there is a big difference between an integer and a date. I changed the calculation using DateDiff, but this requires two dates to compare. In your case using an integer your calculation does the job.

Re: Data Expression for Pie Chart in Dashboard Fails

Anonymous User — Wed, 08 Sep 2021 13:19:09 GMT

Thank you so much for your help!!