noj-book.visualizing-correlation-matrices - WIP

notebooks/noj_book/visualizing_correlation_matrices.clj

@@ -9,8 +9,11 @@
 
 (ns noj-book.visualizing-correlation-matrices
   (:require [fastmath.stats]
+            [fastmath.core :as fastmath]
             [tablecloth.api :as tc]
-            [noj-book.datasets]))
+            [noj-book.datasets]
+            [scicloj.kindly.v4.kind :as kind]
+            [clojure.math :as math]))
 
 ;; ## Auxiliary functions
 
@@ -59,3 +62,51 @@
 ;; For example:
 (-> noj-book.datasets/iris
     (correlations-dataset [:sepal-length :sepal-width :petal-length :petal-width]))
+
+;; ## Drawing a heatmap using Echarts
+
+;; The following function is inspired by
+;; [an Apache Echarts heatmap tutorial](https://github.com/apache/echarts/blob/master/test/heatmap-large.html).
+
+(defn echarts-heatmap [{:keys [xyz-data xs ys
+                               min max
+                               series-name]
+                        :or {series-name ""}}]
+  (kind/echarts
+   {:tooltip {}
+    :xAxis {:type :category
+            :data xs}
+    :yAxis {:type :category
+            :data ys}
+    :visualMap {:min min
+                :max max
+                :calculable true
+                :splitNumber 8
+                :inRange {:color
+                          ["#313695" "#4575b4" "#74add1"
+                           "#abd9e9" "#e0f3f8" "#ffffbf"
+                           "#fee090" "#fdae61" "#f46d43"
+                           "#d73027" "#a50026"]}}
+    :series [{:name series-name
+              :type :heatmap
+              :data xyz-data
+              :itemStyle {:emphasis {:borderColor "#333"
+                                     :borderWidth 2}}
+              :progressive 1000
+              :animation false}]}))
+
+;; Here is an example using synthetic data:
+
+(let [n 30]
+  (echarts-heatmap
+   {:xyz-data (for [i (range n)
+                    j (range n)]
+                [i j (fastmath/logistic (*  (+ (- i j))
+                                            (rand)
+                                            (/ 2 (double n))))])
+    :x-data (range n)
+    :y-data (range n)
+    :min 0
+    :max 1}))
+
+;; Note that this plot supports tooltips.