From 145452d50fe6a60f2d79a57bd3595da9153543b7 Mon Sep 17 00:00:00 2001
From: Ozzie Gooen <ozzieagooen@gmail.com>
Date: Fri, 3 Apr 2020 14:32:14 +0100
Subject: [PATCH] Auto-kernel-width

---
 package.json   |  4 ++--
 src/Samples.re | 11 ++++++++++-
 yarn.lock      |  2 +-
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/package.json b/package.json
index 6d5c6342..332492fa 100644
--- a/package.json
+++ b/package.json
@@ -60,8 +60,8 @@
     "react-use": "^13.27.0",
     "reason-react": ">=0.7.0",
     "reschema": "1.3.0",
-    "tailwindcss": "1.2.0",
-    "science": "1.9.3"
+    "science": "^1.9.3",
+    "tailwindcss": "1.2.0"
   },
   "alias": {
     "react": "./node_modules/react",
diff --git a/src/Samples.re b/src/Samples.re
index 8ccd178c..d7f3b5d2 100644
--- a/src/Samples.re
+++ b/src/Samples.re
@@ -88,6 +88,15 @@ module T = {
     (continuous, discrete);
   };
 
+  let kde = (~samples, ~outputXYPoints) => {
+    let width = Science.nrd0(samples);
+    let xyPointRange = E.A.Sorted.range(samples) |> E.O.default(0.0);
+    let xyPointWidth = xyPointRange /. float_of_int(outputXYPoints);
+    let kernelWidth = int_of_float(Jstat.max([|(width /. xyPointWidth), 1.0 |]));
+    Js.log4(samples, width, xyPointWidth, kernelWidth);
+    KDE.normalSampling(samples, outputXYPoints, kernelWidth);
+  };
+
   // todo: Figure out some way of doing this without having to integrate so many times.
   let toShape = (~samples: t, ~outputXYPoints=3000, ~kernelWidth=10, ()) => {
     Array.fast_sort(compare, samples);
@@ -102,7 +111,7 @@ module T = {
     let pdf: DistTypes.xyShape =
       continuousPart |> E.A.length > 5
         ? {
-          continuousPart |> KDE.normalSampling(_, outputXYPoints, kernelWidth);
+          continuousPart |> kde(~samples=_, ~outputXYPoints)
         }
         : {xs: [||], ys: [||]};
     let continuous = pdf |> Distributions.Continuous.make(`Linear);
diff --git a/yarn.lock b/yarn.lock
index 01e751af..b3c000da 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8579,7 +8579,7 @@ scheduler@^0.19.0:
     loose-envify "^1.1.0"
     object-assign "^4.1.1"
 
-science@1.9.3:
+science@^1.9.3:
   version "1.9.3"
   resolved "https://registry.yarnpkg.com/science/-/science-1.9.3.tgz#ec89bac44aeff2e5a2d749aa496f377089903dd4"
   integrity sha1-7Im6xErv8uWi10mqSW83cImQPdQ=