Julia implementation

soln-julia/utils.jl

@@ -0,0 +1,78 @@
+
+module Utils
+# check that a package is installed
+function checkpkgs(pkglist::Vararg{AbstractString, N}) where N
+    missing = []
+    for p in pkglist
+        pkg = Symbol(p)
+        try
+            @eval using $pkg
+        catch e
+            push!(missing, p)
+        end
+    end
+    if length(missing) > 0
+        m = join(missing, ", ")
+        error("""These packages are missing: $m
+                 You can install with e.g. :
+                    import Pkg; Pkg.add("$(missing[1])")
+            """
+        )
+    end
+end
+
+checkpkgs("Downloads", "Plots", "Distributions", "DataFrames", "Loess", "Gumbo", "HTTP", "Cascadia")
+
+import Downloads, DataFrames, Loess, Plots, Distributions
+import Gumbo, Cascadia, HTTP, CSV
+
+function getfile(url::String)
+    filename = basename(url)
+    if !isfile(filename)
+        _local = Downloads.download(url, filename)
+        println("Downloaded ", _local)
+    end
+end
+
+default(linewidth=2, legend=false, size = (480, 320)); 
+
+function Base.transpose(df::DataFrame; col_names=nothing)
+    tdf = DataFrames.DataFrame(collect.(eachrow(df)), :auto)
+    isnothing(col_names) || rename!(tdf, col_names)
+    return tdf
+end
+
+function plotloess!(xs, ys; kwargs...)
+    model = Loess.loess(xs, ys)
+    us = range(extrema(xs)...; length = 101)
+    vs = Loess.predict(model, us)
+    Plots.plot!(us, vs; kwargs...)
+end
+
+# this is a hack
+# unfortunately, there's no Julia equivalent for Pandas' read_html
+function retrievetables(url::String; kwargs...)
+    res = HTTP.request("GET",url)
+    g = Gumbo.parsehtml(String(res.body))
+
+    delim="∘"
+    tbls = eachmatch(Cascadia.Selector("tbody"), g.root)
+    v = []
+    for tbl in tbls
+        rows = children(tbl)
+        io = IOBuffer()
+        # this is an ugly hack: convert to CSV and let CSV deal with the mess
+        # (hopefully, parsing types correctly)
+        for row in rows
+            entries = [strip(nodeText(c)) for c in children(row)]
+            println(io, join(entries, delim))
+        end
+        seekstart(io)
+        df = CSV.File(io, delim=delim; kwargs...) |> DataFrame
+        push!(v, df)
+    end
+    return v
+end
+
+export checkpkgs, retrievetables, transpose, plotloess!, getfile
+end;