Add histogram spec

Author: darthjee

spec/integration/histtest_spec.rb

@@ -0,0 +1,48 @@
+describe "Histogram Plot Example" do
+  let(:file_path)    { 'spec/tmp/histogram_plot.eps' }
+  let(:fixture_path) { 'spec/fixtures/plots/histogram_plot.eps' }
+
+  let(:file_content) do
+    File.read(file_path).gsub(/CreationDate.*/, "")
+  end
+
+  let(:fixture_content) do
+    File.read(fixture_path).gsub(/CreationDate.*/, "")
+  end
+
+  before do
+    path = file_path
+    collection = (0..500).collect do |_v|
+      (rand()-0.5)**3
+    end
+
+    Gnuplot.open do |gp|
+      gp << "bin(x, s) = s*int(x/s)\n"
+
+      Gnuplot::Plot.new( gp ) do |plot|
+        plot.title  "Histogram"
+        plot.xlabel "x"
+        plot.ylabel "frequency"
+
+        plot.data << Gnuplot::DataSet.new( [collection] ) do |ds|
+          ds.title = "smooth frequency"
+          ds.using = "(bin($1,.01)):(1.)"
+          ds.smooth = "freq"
+          ds.with = "boxes"
+        end
+
+        plot.term   "postscript eps"
+        plot.output path
+      end
+    end
+
+  end
+
+  after do
+    File.delete(file_path)
+  end
+
+  it "plots expected file" do
+    expect(file_content).to eq(fixture_content)
+  end
+end