From 38c97d9e260e336e936258c126e742e7ab22afa5 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Sun, 19 Aug 2012 17:42:08 -0400
Subject: [PATCH] Don't plot missing surface detection regions in
 analyze_surface_position_data.

This allows us to use the surface-matplotlib option to debug the
surface-position algorithm even when it's used on phony data that only
contains 'approach'.
---
 pypiezo/surface.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pypiezo/surface.py b/pypiezo/surface.py
index 4cea70d..be696f4 100644
--- a/pypiezo/surface.py
+++ b/pypiezo/surface.py
@@ -222,7 +222,8 @@ def analyze_surface_position_data(
                        ('ret2', 'second retract'),
                        ('approach', 'main approach'),
                        ('ret3', 'return to start')]:
-            axes.plot(ddict[n]['z'], ddict[n]['deflection'], label=name)
+            if n in ddict:
+                axes.plot(ddict[n]['z'], ddict[n]['deflection'], label=name)
         def fit_fn(x, params):
             if x <= params[2]:
                 return params[0] + params[1]*x
-- 
2.26.2