Need help with Arcade Data Expression in Dashboard

M_M — Thu, 09 Mar 2023 07:13:37 GMT

I am new to Arcade and have found myself stuck. I am writing a data expression for dashboard and I can't figure out how to write a calculation. I get an error with everything I've tried.

I need to multiply the Tally field for records with a 'Plot_Size' of 0.02 by 50, and multiply any records with a 'Plot_Size' of 0.01 by 100.
I created a filter to parse out records with 'Plot_Size' 0.02 & 0.01. I tried to create a new var plot_exp to do the calculation but it's not working (line 10).
I also tried to do the calculation in my GroupBy (line 20) and it's not recognizing the var I created in the filters on line 6-7.

I also tried to create a dictionary, and use that but I couldn't get that to work either 🙂

My end goal is to multiply the 'Tally' field for each 'Stand_No' by 50 or 100 (as determined by 'Plot_Sizes' of 0.02 and 0.01). I then need to find the average for those new (Tally*50 and Tally*100) numbers for each 'Stand_No'.

var p = 'https://maps.arcgis.com' var itemId = 'a8af124e92af44579e3fd07bb59ebb4c' var fs = FeatureSetByPortalItem(Portal(p), itemId, 0, ['Stand_No', 'Tally', 'Plot_Configuration', 'Plot_Name', 'Plot_Status', 'Plot_Size', 'DBH', 'Height', 'Cruiser_Name', 'Exit_Plot_Time'], false) //Separate Plot Size into 2 groups for planting var plot50 = Filter(fs, 'Plot_Size = (0.02)'); var plot100 = Filter(fs, 'Plot_Size = (0.01)'); var TPS = 0 //Multiply the plot size in plot50 by 2,500, multiply the plot size in plot100 by 10,000) var plot_exp = [{name: 'TPS', expression: '(Tally * 2500)', statistic: 'MAX'}] //return plot_exp var summary = GroupBy(fs,['Stand_No','Plot_Configuration','Plot_Size', 'Cruiser_Name'], [{name: 'TallySum', expression: 'Tally', statistic: 'SUM'}, {name: 'TCount', expression: '1', statistic: 'COUNT'}, {name: 'AvgDBH', expression: 'DBH', statistic: 'AVG'}, {name: 'AvgHeight', expression: 'Height', statistic: 'AVG'}, {name: '50TPS', expression: '(@plot50 * 2500)', statistic: 'AVG'}]) Console(summary) return summary //Goal is to obtain the Trees per Acre per Stand for each Stand

Re: Need help with Arcade Data Expression in Dashboard

jcarlson — Thu, 09 Mar 2023 14:17:41 GMT

The SQL expressions used in GroupBy will recognize numeric and text data, but not objects like FeatureSets. If you need to apply a different calculation based on a field's value, you can do that in the SQL expression using CASE.

var plot_exp = `CASE WHEN Plot_Size = 0.02 THEN Tally * 0.02 WHEN Plot_Size = 0.01 THEN Tally * 0.01 ELSE Tally -- or some other default value END`

Just swap that in as one of the expressions in your GroupBy function, and you should get results like you expect.

Re: Need help with Arcade Data Expression in Dashboard

M_M — Thu, 09 Mar 2023 17:07:33 GMT

That works perfectly, thank you so much!! I really appreciate the help! 🙂

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Need help with Arcade Data Expression in Dashboard

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