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Created February 14, 2013 19:17
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Run k-means clustering on list of cities and plot results as labeled scatterplot in Excel
type City = { Name: string; Lat: float; Lng: float }
let cities =
[ ("San Francisco", "CA", "United States");
("New York", "NY", "United States");
("Hoboken", "NJ", "United States");
("Redmond", "WA", "United States");
("Seattle", "WA", "United States");
("Boston", "MA", "United States");
("Boston", "MA", "United States");
("Romeoville", "IL", "United States");
("Nashville", "TN", "United States");
("Nashville", "TN", "United States");
("Detroit", "MI", "United States");
("Ann Harbor", "MI", "United States");
("Houston", "TX", "United States") ]
let rng = new System.Random()
let fakeService (data: (string * string * string)) =
let city, state, country = data
{ Name = city; Lat = rng.NextDouble(); Lng = rng.NextDouble() }
// extraction of cities
let positions = cities |> List.map fakeService
// k-means clustering
let pos = positions |> List.map (fun c -> [| c.Lat; c.Lng |])
let factory (ps: (float []) seq) (k: int) = randomCentroids rng pos k
let analysis = kmeans euclidean factory avgCentroid (List.map (fun p -> [| p.Lat; p.Lng |]) positions)
// plot clusters
let plotClusters k =
let centers, classifier = analysis k
let datapoints =
positions
|> List.map (fun c -> c, [| c.Lat; c.Lng |])
|> List.map (fun (c, p) -> c, List.findIndex (fun c -> c = classifier p) centers)
|> List.map (fun (c, i) -> (c.Lat, c.Lng, i, c.Name))
let centroids = centers |> List.map (fun c -> c.[0], c.[1], -1, "CENTROID")
List.append datapoints centroids |> labeledplot
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