Arcade expression for Min, Max, Avg and Count

[User1RECS]

I am working on the typology of urban blocks. Each block contains a number of buildings, each of which has an area and a height.
I would like to calculate the maximum, minimum, average and median area and height in each block on arcade. Can you help me please?

[JohannesLindner]

• You need a table with a block id, building height, and building area
• You need one of the FeatureSetBy*() functions to load your building data
• You need the GroupBy() function to group your building data by block id.

For the functions, look here:

https://developers.arcgis.com/arcade/function-reference/data_functions/#featuresetbyid

https://developers.arcgis.com/arcade/function-reference/data_functions/#groupby 

As an example, you can use the following code in the Playground | ArcGIS Arcade | ArcGIS Developer

var fs_buildings = {
    "geometryType": "",
    "fields": [
        {"name": "BlockID", "type": "esriFieldTypeInteger"},
        {"name": "BuildingID", "type": "esriFieldTypeInteger"},
        {"name": "BuildingHeight", "type": "esriFieldTypeDouble"},
        {"name": "BuildingArea", "type": "esriFieldTypeDouble"}
        ],
    "features": [
        {"attributes": {"BlockID": 1, "BuildingID": 1, "BuildingHeight": 10., "BuildingArea": 300.}},
        {"attributes": {"BlockID": 1, "BuildingID": 2, "BuildingHeight": 30., "BuildingArea": 500.}},
        {"attributes": {"BlockID": 1, "BuildingID": 3, "BuildingHeight": 15., "BuildingArea": 250.}},
        {"attributes": {"BlockID": 2, "BuildingID": 4, "BuildingHeight": 16., "BuildingArea": 400.}},
        {"attributes": {"BlockID": 2, "BuildingID": 5, "BuildingHeight": 10., "BuildingArea": 300.}},
        {"attributes": {"BlockID": 3, "BuildingID": 6, "BuildingHeight": 10., "BuildingArea": 300.}}
        ]
}
fs_buildings = FeatureSet(Text(fs_buildings))
//return fs_buildings

// actually use one of the FeatureSetBy*() functions:
//var p = Portal(...)
//var fs_buildings = FeatureSetByPortalItem(p, item, layer, ["BlockID", "BuildingID", "BuildingHeight", "BuildingArea"], false)

var statistics = [
    {"name": "Count", "expression": "BuildingID", "statistic": "COUNT"},
    {"name": "HeightMax", "expression": "BuildingHeight", "statistic": "MAX"},
    {"name": "HeightMin", "expression": "BuildingHeight", "statistic": "MIN"},
    {"name": "HeightMean", "expression": "BuildingHeight", "statistic": "AVG"},
    {"name": "AreaMax", "expression": "BuildingArea", "statistic": "MAX"},
    {"name": "AreaMin", "expression": "BuildingArea", "statistic": "MIN"},
    {"name": "AreaMean", "expression": "BuildingArea", "statistic": "AVG"},
    ]
var fs_grouped_buildings = GroupBy(fs_buildings, "BlockID", statistics)
return fs_grouped_buildings

[User1RECS]

Thank you very much for your quick response

in fact I already have a table with the BlockID, the ID of the buildings, the area and the height of each building. and I would like to calculate from this table.

[User1RECS]

could you, please, tell me how to calculate each statistic by adding a new field on my buildings table and calculating the field?

[JohannesLindner · Accepted solution]

If you want to do this in the CalculateField tool, you can use this expression, modified for each statistic:

// load the whole feature class
var fs_buildings = FeatureSetByName($datastore, "BuildingFC", ["BlockID", "BuildingID", "BuildingHeight", "BuildingArea"], false)

// only select rows with the current feature's BlockID
var id = $feature.BlockID
var fs_buildings_block = Filter(fs_buildings, "BlockID = @ID")

// edit this line for each statistic and field
return Min(fs_buildings_block, "BuildingHeight")

[User1RECS]

IT work...Thank you very much !!!!