diff --git a/reflowctl/reflowctl_gui.py b/reflowctl/reflowctl_gui.py
index 4d3390e..5e9fb22 100755
--- a/reflowctl/reflowctl_gui.py
+++ b/reflowctl/reflowctl_gui.py
@@ -51,6 +51,8 @@ class Plotter(FigureCanvas):
         self.selx = list()
         self.sely = list()
 
+        self.selected_ix = 0
+
         self.setParent(parent)
         self.myapp = myapp
         self.solder = None
@@ -81,8 +83,7 @@ class Plotter(FigureCanvas):
     def set_picked(self, ix):
         if isinstance(ix, QtCore.QModelIndex):
             ix = ix.row()
-        self.selx = numpy.array(map(float, self.x[ix:ix + 2]))
-        self.sely = numpy.array(map(float, self.y[ix:ix + 2]))
+        self.selected_ix = ix
         self.updated = True
 
     def update_figure(self):
@@ -105,6 +106,9 @@ class Plotter(FigureCanvas):
             self.plot_data.set_xdata(self.x)
             self.plot_data.set_ydata(self.y)
 
+            self.selx = numpy.array(map(float, self.x[self.selected_ix:self.selected_ix + 2]))
+            self.sely = numpy.array(map(float, self.y[self.selected_ix:self.selected_ix + 2]))
+
             self.selection_data.set_xdata(self.selx)
             self.selection_data.set_ydata(self.sely)