GUI: allow enums to be plotted

numpy.finite() does not accept enums -> convert to float first

Change-Id: Ib740800a7410ada38fb48711d4da676af8b64b17
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/34608
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

frappy/gui/plotting.py

@@ -131,7 +131,7 @@ class PlotWidget(QWidget):
         curve = self.curves[name]
         x,y = self.data[name]
         x = np.append(x, value.timestamp)
-        y = np.append(y, value.value)
+        y = np.append(y, float(value.value))
         self.data[name] = (x,y)
         curve.setData(x,y)