From: W. Trevor King <wking@drexel.edu>
Date: Mon, 26 Mar 2012 18:00:36 +0000 (-0400)
Subject: Add Piezo.zero().
X-Git-Tag: 0.7~11
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=4c0eb4fdc2f6ada14bd98bdd510e59889945fd59;p=pypiezo.git

Add Piezo.zero().
---

diff --git a/pypiezo/afm.py b/pypiezo/afm.py
index a7cb9d5..402ac18 100644
--- a/pypiezo/afm.py
+++ b/pypiezo/afm.py
@@ -81,9 +81,8 @@ class AFMPiezo (_base.Piezo):
     We need to know where we are before we can move somewhere
     smoothly.
 
-    >>> pos = _base.convert_volts_to_bits(p.config.select_config(
-    ...     'axes', 'z', get_attribute=_base.get_axis_name)['channel'], 0)
-    >>> p.jump('z', pos)
+    >>> zeros = p.zero(axis_names=['z'])
+    >>> pos = zeros[0]
 
     Usually `.move_to_pos_or_def` is used to approach the surface, but
     for testing we assume the z output channel is connected directly
diff --git a/pypiezo/base.py b/pypiezo/base.py
index 6f9eefc..25461c7 100644
--- a/pypiezo/base.py
+++ b/pypiezo/base.py
@@ -912,3 +912,16 @@ class Piezo (object):
         for i,name in enumerate(input_names):
             ret[name] = input_data[:,i]
         return ret
+
+    def zero(self, axis_names=None, **kwargs):
+        zeros = []
+        if axis_names is None:
+            axis_names = [axis.name for axis in self.axes]
+        for axis_name in axis_names:
+            axis = self.axis_by_name(axis_name)
+            config = self.config.select_config(
+                'axes', axis_name, get_attribute=get_axis_name)['channel']
+            zero = convert_volts_to_bits(config, 0)
+            zeros.append(zero)
+            self.jump(axis_name, zero)
+        return zeros