Clustering Feature Reduction using UniqueValueRenderer based on value from another field

LawrenceD — Mon, 23 Sep 2024 14:53:35 GMT

I am using Clustering Featured Reduction (ArcGIS Maps SDK 4.30) on a Feature Layer with UniqueValueRender for symbols for a category. By default, the API will symbolize the cluster based on the "predominant category". Where predominant seems to refer to the most frequent category in the cluster.

I want to use the symbol for the category with the highest value of a particular field in the cluster. As an example, my data contains a category called animals, and a particular cluster has 3 cats and a dog, the API assigns the cluster the symbol of a cat. In my data, I have an additional field, the price for each animal, and the dog has the highest cost of all animals, I would like to assign the cluster the symbol of a dog.

What I have tried:

Using UniqueValueRender value expression Arcade. From here I am able to access the cluster feature, summary stats (computed in the cluster configuration), but the attributes here do not contain the aggregated features. So I am not able to find out which of the cluster elements contain the highest value.

//Expects($Feature, '*') { "attributes": { "aggregateId": "266.187", "cluster_count": 12, "max_price": 100.0001, "avg_price": 23.674746264166668, "count_animals": 12, "unique_id": "db4120ae-b6be-4cc2-b20e-0a10c388d829", "category": "Dog" }, "geometry": { "x": 108, "y": 178 }, "centroid": { "x": 108, "y": 178 } }

I have also tried creating a new category field from the aggregated features. The Arcade below will work fine to present this information in a pop up, so I would be able to find out the category with the highest value from $aggregatedFeatures

{ label: 'Predominant category', type:'expression', expressionInfo: { expression: ` Expects($aggregatedFeatures, '*'); var statsFs = GroupBy($aggregatedFeatures, [ { name: 'Type', expression: 'category'} ], [ { name: 'MaxPrice', expression: 'price', statistic: 'MAX' } ] ); var ordered = Top(OrderBy(statsFs, 'MaxPrice DESC'), 5); // create an HTML ordered list as a string and return in a rich text element var list = "<p>Top animals (Price)</p><ol>"; for (var cat in ordered){ list += \`<li>\${cat.Type} (\${Text(cat.MaxPrice)}) </li>\` } list += "</ol>"; return { type: "text", text: list } ` } }

However trying the same approach in the fields definition does not work, as $aggregatedFeatures does not seem to exist.

{ name: 'pred_cat', onStatisticExpression: { title: 'category', returnType: 'string', expression: ` //Works fine, but I have only access to a single feature not all cluster features Expects($feature, '*') //Error Expects($aggregatedFeatures, '*') return "Dog" ` } ,statisticType: 'mode' }

How can I achieve this? Thank you.

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Clustering Feature Reduction using UniqueValueRenderer based on value from another field