Issue #2999560 by laboratory.mike: How to create a true scatter chart?

modules/charts_c3/src/Plugin/chart/C3.php

@@ -142,22 +142,18 @@ class C3 extends AbstractChart {
       // C3 does not use bar, so column must be used.
       if ($options['type'] == 'bar') {
         $chartAxis->setRotated(TRUE);
-        array_unshift($categories, 'x');
-        array_push($c3Data, $categories);
-        $chartData->setColumns($c3Data);
       }
       elseif ($options['type'] == 'column') {
         $chartData->setType('bar');
         $chartAxis->setRotated(FALSE);
-        array_unshift($categories, 'x');
-        array_push($c3Data, $categories);
-        $chartData->setColumns($c3Data);
       }
-      else {
-        array_unshift($categories, 'x');
-        array_push($c3Data, $categories);
-        $chartData->setColumns($c3Data);
+      if ($options['type'] == 'scatter') {
+        $chartAxis->setX(['tick' => ['fit' => FALSE]]);
       }
+
+      array_unshift($categories, 'x');
+      array_push($c3Data, $categories);
+      $chartData->setColumns($c3Data);
       $c3->setAxis($chartAxis);
     }
 

modules/charts_c3/src/Settings/CThree/ChartAxis.php

@@ -31,6 +31,26 @@ class ChartAxis implements \JsonSerializable {
     $this->rotated = $rotated;
   }
 
+  /**
+   * Get X.
+   *
+   * @return mixed $x
+   *   Data for X Axis.
+   */
+  public function getX() {
+    return $this->x;
+  }
+
+  /**
+   * Set X.
+   *
+   * @param mixed $x
+   *   Data for X Axis.
+   */
+  public function setX($x) {
+      $this->x = $x;
+  }
+
   /**
    * Json Serialize.
    *