Merge pull request #1 from snotskie/master

Added direct plotting for Polynomial.Poly objects

Author: chriddyp

README.md

@@ -35,6 +35,20 @@ That last line is what the REPL prints out,
 as a Firefox tab opens with the plot.
 You can also just call `plot` by itself, and you'll get a String that's the url of your chart.
 
+## Plot Functions and Polynomials
+    julia> Plotly.plot(abs)
+    julia> Plotly.plot([sqrt, log], ["left"=>10, "right"=>20, "step"=>0.1])
+
+You can now plot functions directly.
+The first line shows how to plot the absolute value function, and the second line plots
+the square root and logarithm functions, both from 10 to 20 at increments of 0.1.
+
+    julia> using Polynomial
+    julia> x = Poly([1,0])
+    julia> Plotly.plot(3x^3 + 2x^2 - x + 1)
+
+If you have the Polynomial package installed, you can plot them directly the same way as math functions.
+
 ## Style and Layout
     julia> Plotly.style(["line"=>["color"=>"rgb(255,0,0)","width"=>10]])
 

src/Plotly.jl

@@ -79,6 +79,8 @@ function plot(data::Array,options=Dict())
     end
 end
 
+include("plot.jl")
+
 function layout(layout_opts::Dict,meta_opts=Dict())
     global plotlyaccount
     if !isdefined(Plotly,:plotlyaccount)

src/plot.jl

@@ -0,0 +1,36 @@
+function get_points(f::Function, options=Dict())
+	opt = merge(["left"=>-10, "right"=>10, "step"=>0.5, "name"=>"$f"], options)
+	n::Int = (opt["right"] - opt["left"]) / opt["step"] + 1
+	X = Float64[0 for i in 1:n]
+	Y = Float64[0 for i in 1:n]
+	for i in 1:n
+		x = opt["step"]*(i-1) + opt["left"]
+		y = f(x)
+		X[i] = round(x, 8)
+		Y[i] = round(y, 8)
+	end
+
+	return ["x"=>X, "y"=>Y, "type"=>"scatter", "mode"=>"lines", "name"=>opt["name"]]
+end
+
+function plot(fs::Array{Function,1}, options=Dict())
+	data = [get_points(f, options) for f in fs]
+	return plot([data], options)
+end
+
+function plot(f::Function, options=Dict())
+	return plot([f], options)
+end
+
+if Pkg.installed("Polynomial") !== nothing
+	using Polynomial
+
+	function plot{T<:Number}(ps::Array{Poly{T},1}, options=Dict())
+		data = [get_points(x->polyval(p,x), merge(["name"=>"$p"], options)) for p in ps]
+		return plot([data], options)
+	end
+
+	function plot(p::Poly, options=Dict())
+		return plot([p], options)
+	end
+end