From 0b453ae5346304826faef59f138fa652958e7e41 Mon Sep 17 00:00:00 2001
From: Davide Faconti <davide.faconti@gmail.com>
Date: Sun, 9 Feb 2020 15:02:25 +0100
Subject: [PATCH] preliminary change to support #244 (#247)

---
 plotter_gui/transforms/custom_function.cpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/plotter_gui/transforms/custom_function.cpp b/plotter_gui/transforms/custom_function.cpp
index 2c1b3170b..c0c6a1a9a 100644
--- a/plotter_gui/transforms/custom_function.cpp
+++ b/plotter_gui/transforms/custom_function.cpp
@@ -152,7 +152,22 @@ PlotData::Point CustomFunction::calculatePoint(QJSValue& calcFct,
     {
         throw std::runtime_error("JS Engine : " + jsData.toString().toStdString());
     }
-    new_point.y = jsData.toNumber();
+
+    if( jsData.isArray() )
+    {
+      const int length = jsData.property("length").toInt();
+      if( length == 2 )
+      {
+        new_point.x = jsData.property(0).toNumber();
+        new_point.y = jsData.property(1).toNumber();
+      }
+      else{
+        throw std::runtime_error("JS Engine : if you return an array, the size must be 2 (time/value pair)");
+      }
+    }
+    else{
+      new_point.y = jsData.toNumber();
+    }
 
     return new_point;
 }