jupyter support for evilplot (#334)

* include almond jupyter support in rainier-plot

* fix build

* aesthetics

* warnings

* formatting

* example ipynb

.gitignore

@@ -5,3 +5,4 @@ target/
 .DS_Store
 .bloop/
 .metals/
+.ipynb_checkpoints/

build.sbt

@@ -73,6 +73,8 @@ lazy val V = new {
   val scalacheck = "1.14.0"
   val scalatest = "3.0.5"
   val flogger = "0.3.1"
+  val almond = "0.3.0"
+  val scala = "2.12.8"
   val shadedAsm = "0.2.1"
 }
 
@@ -95,8 +97,15 @@ lazy val rainierPlot = project.
   dependsOn(rainierCore).
   settings(commonSettings).
   settings(
-    resolvers += Resolver.bintrayRepo("cibotech", "public"),
-    libraryDependencies += "com.cibo" %% "evilplot" % V.evilplot)
+    resolvers ++= 
+      Seq(
+        Resolver.bintrayRepo("cibotech", "public"),
+        "jitpack" at "https://jitpack.io"),
+    libraryDependencies ++= 
+      Seq(
+        "com.cibo" %% "evilplot" % V.evilplot,
+        "sh.almond" %% "interpreter-api" % V.almond)
+  )
 
 lazy val rainierCats = project.
   in(file("rainier-cats")).

rainier-plot/src/main/scala/com/stripe/rainier/plot/EvilTracePlot.scala

@@ -32,6 +32,25 @@ object EvilTracePlot {
     ()
   }
 
+  /**
+    * Render plots to a PNG byte array
+    *
+    * @param plots A collection of plots, possibly produced by `traces` or `pairs`
+    * @param extent The size of the image to be rendered
+    */
+  def renderBytes(plots: List[List[com.cibo.evilplot.plot.Plot]],
+                  extent: com.cibo.evilplot.geometry.Extent): Array[Byte] = {
+    val baos = new java.io.ByteArrayOutputStream
+    javax.imageio.ImageIO
+      .write(
+        com.cibo.evilplot.plot.Facets(plots).render(extent).asBufferedImage,
+        "png",
+        baos)
+    val array = baos.toByteArray
+    baos.close
+    array
+  }
+
   /**
     * Autocorrelation function
     *

rainier-plot/src/main/scala/com/stripe/rainier/plot/Jupyter.scala

@@ -0,0 +1,27 @@
+package com.stripe.rainier.plot
+
+import almond.interpreter.api._
+import com.cibo.evilplot.geometry._
+
+object Jupyter {
+  def traces(out: Seq[Map[String, Double]],
+             truth: Map[String, Double] = Map(),
+             lagMax: Int = 40,
+             numBars: Int = 50)(implicit outputHandler: OutputHandler): Unit =
+    DisplayData
+      .png(
+        EvilTracePlot.renderBytes(
+          EvilTracePlot.traces(out, truth, lagMax, numBars),
+          Extent(1200, out.head.keys.size * 300.0)))
+      .show()
+
+  def pairs(out: Seq[Map[String, Double]],
+            truth: Map[String, Double] = Map(),
+            numBars: Int = 30)(implicit outputHandler: OutputHandler): Unit =
+    DisplayData
+      .png(
+        EvilTracePlot.renderBytes(EvilTracePlot.pairs(out, truth, numBars),
+                                  Extent(out.head.keys.size * 300.0,
+                                         out.head.keys.size * 300.0)))
+      .show()
+}