add an example to manual

Author: sl-solution

docs/make.jl

@@ -36,7 +36,8 @@ makedocs(
         "Interactive" => [
             "Pyramid" => "man/pyramid.md",
             "Nations" => "man/nations.md",
-            "Movies" => "man/movies.md"
+            "Movies" => "man/movies.md",
+            "Polygon" => "man/polygon.md"
         ],
         "API" => Any[
             "Functions" => "lib/functions.md",

docs/src/man/polygon.md

@@ -0,0 +1,41 @@
+# Example
+
+```@example
+using InMemoryDatasets, StatisticalGraphics
+
+function npolygon(n, sangle, radius)
+    stepsize = 360 / n
+    res = Vector{Tuple{Float64,Float64}}(undef, n)
+    for i in 1:n
+        degree = (i - 1) * stepsize + sangle
+        res[i] = (cosd(degree) * radius, sind(degree) * radius)
+    end
+    res
+end
+
+
+ds = Dataset(sangle=range(0, 500, step=10))
+insertcols!(ds, :radius => [0.95^i for i in 0:nrow(ds)-1])
+insertcols!(ds, :n => (3:8...,))
+flatten!(ds, :n)
+modify!(ds, (3, 1, 2) => byrow(npolygon) => :polygon)
+modify!(ds, :polygon => byrow(x -> 1:length(x)) => :vert)
+flatten!(ds, [:polygon, :vert])
+modify!(ds, :polygon => splitter => [:x, :y])
+modify!(ds, :radius => byrow(x -> 1.1 - x) => :opacity)
+
+sgmanipulate(groupby(ds, :n),
+             Polygon(x=:x, y=:y, id=:sangle,
+                        opacityresponse=:opacity,
+                        colorresponse=:opacity,
+                        outlinecolor=:white,
+                        outlinethickness=0.5
+                    ),
+                    nominal=:opacity,
+                    width=400,
+                    xaxis=Axis(show=false),
+                    yaxis=Axis(show=false),
+                    legend=false,
+                    wallcolor=:lightgray
+            )
+```