A gnuplot example.

examples.md

@@ -89,6 +89,14 @@ for plotting or rendering graphics.
 -   [Generating videos with literate Futhark](examples/literate-video.html)
 -   [Reading and writing files in literate Futhark](examples/literate-files.html)
 
+# Plotting
+
+Literate Futhark allows direct use of
+[gnuplot](http://www.gnuplot.info/). These examples show simple and
+common cases.
+
+- [Plotting a histogram](examples/plot-histogram.html)
+
 # Examples from Dex
 
 The following examples are ported from

examples/plot-histogram.fut

@@ -0,0 +1,22 @@
+-- # Plotting a histogram
+
+-- This can be done by computing a histogram in Futhark and then using
+-- a box plot. Here we produce some arbitrary values, discretised aong
+-- *k* bins.
+
+def plot k n : ([]i64,[]i32) =
+  let vs = iota n |> map (f64.i64 >-> f64.cos >-> (+1) >-> (*(f64.i64 k/2)) >-> i64.f64)
+  in (iota k,
+      hist (+) 0 k vs (replicate n 1))
+
+-- > :gnuplot {data=plot 100 10000};
+-- set xrange [0:100];
+-- set style fill solid 1.0
+-- plot data with boxes
+
+
+-- ## See also
+--
+-- [Gnuplots built-in support for histograms](http://gnuplot.info/docs_6.1/loc5256.html).
+--
+-- [Generalised histograms.](histogram.html).