Include sum and average in bar chart using data expression/arcade

Question

I am trying to write a data expression that finds the count of that field. Then calculates the average of a field (filter/selection dependent) and use that in a bar chart along with the sum of another field.

In the picture below, I am trying to get the Target Goal to be 12 (24/2 records) while the Target Value (14) is the sum of 2 values.

var fs = FeatureSetByPortalItem(
  Portal("https://www.arcgis.com/"),
  "384158f2ebe34f8ba8b0b39dfe5f5af5",
  0,
  [
    'Jurisdiction', 
    'core_capability', 
    'target',
    'target_goal',
    'target_value_final'],
  false
);

var tar_goal = $feature.target_goal

var tar_final = Filter(fs, "target_goal = @tar_goal")

//find the total count of tar_final
var tar_count =  Count(tar_final)

//find sum of target_goal
var goal_sum = Sum($feature, tar_goal)

//Divide the sum of target_goal by target goal count
var targets = goal_sum/tar_count

return targets

@JohannesLindner

dwold · Answer

Are you wanting the "goal" value to come from the selected feature?  - yes but it isn't a deal breaker for my case. I am trying to find the average of target_goal and use that as a field in my bar chart. If I do group by would it look something like this? Perhaps I am doing this all wrong.

var fs = FeatureSetByPortalItem(
  Portal("https://www.arcgis.com/"),
  "384158f2ebe34f8ba8b0b39dfe5f5af5",
  0,
  [
    'Jurisdiction', 
    'core_capability', 
    'target',
    'target_goal',
    'target_value_final'],
  false
);

var goal_group = GroupBy(fs, 'target_goal', {name: 'Goal', statistic: 'Count'})

var value_group = GroupBy(fs, 'target_value_final', {name: 'Goal', statistic: 'Sum'})

var end_value = value_group / goal_group

return end_value

jcarlson · Answer

Remember, you need to return a FeatureSet from a Data Expression. Also, in a Data Expression, there is no global $feature.

You can get the count and sum both out of a GroupBy function, and even do some derived values involving multiple fields.

The tricky part is "filter/selection dependent". Aggregating in a Data Expression is going to break any kind of per-feature identification in the data.

Are you wanting the "goal" value to come from the selected feature? I don't believe there's a way to pipe values into a data expression from the dashboard's interactivity.