From 1ecb3a3a26f5cbd82a5bded3b8b51fca5affec93 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Wed, 8 Sep 2010 15:45:20 -0400
Subject: [PATCH] Improve handling of the base calibration slot units in JPK
 driver.

---
 hooke/driver/jpk.py | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/hooke/driver/jpk.py b/hooke/driver/jpk.py
index 760d9f1..4e5ab0f 100644
--- a/hooke/driver/jpk.py
+++ b/hooke/driver/jpk.py
@@ -199,20 +199,24 @@ class JPKDriver (Driver):
             'raw info':params,
             #'time':self._time_from_TODO(raw_info[]),
             }
-        force_unit = self._zip_segment_conversion_unit(
-            chan_info['channel']['vDeflection']['conversion-set']['conversion']['force'],
+        force_unit = self._zip_unit(
+            chan_info['channel']['vDeflection']['conversion-set']['conversion']['force']['scaling'],
             version)
         assert force_unit == 'N', force_unit
         force_base = chan_info['channel']['vDeflection']['conversion-set']['conversion']['force']['base-calibration-slot']
         assert force_base == 'distance', force_base
-        dist_unit = self._zip_segment_conversion_unit(
-            chan_info['channel']['vDeflection']['conversion-set']['conversion']['distance'],
+        dist_unit = self._zip_unit(
+            chan_info['channel']['vDeflection']['conversion-set']['conversion']['distance']['scaling'],
             version)
         assert dist_unit == 'm', dist_unit
         distance_base = chan_info['channel']['vDeflection']['conversion-set']['conversion']['distance']['base-calibration-slot']
         assert distance_base == 'volts', distance_base
-        # Assume volts unit is V, but it is not specified in the JPK
-        # file format.
+        base_conversion = chan_info['channel']['vDeflection']['conversion-set']['conversions']['base']
+        assert base_conversion == distance_base, base_conversion
+        distance_base_unit = self._zip_unit(
+            chan_info['channel']['vDeflection']['data'],
+            version)
+        assert distance_base_unit == 'V', distance_base_unit
         force_mult = float(
             chan_info['channel']['vDeflection']['conversion-set']['conversion']['force']['scaling']['multiplier'])
         sens_mult = float(
@@ -278,12 +282,11 @@ class JPKDriver (Driver):
         if conversion == None:
             conversion = conversion_set['conversions']['default']
         if conversion == conversion_set['conversions']['base']:
-            # Our conversion is the base data.
-            if conversion != 'volts':
-                raise NotImplementedError(
-                    'unknown units for base channel: %s' % conversion)
             segment.info['columns'][channel] = join_data_label(
-                channel_name, 'V')
+                channel_name,
+                self._zip_unit(
+                    segment.info['raw info']['channel'][channel_name]['data'],
+                    version))
             return segment
         conversion_info = conversion_set['conversion'][conversion]
         if conversion_info['base-calibration-slot'] \
@@ -312,16 +315,16 @@ class JPKDriver (Driver):
             conversion_info['scaling']['style']
         multiplier = float(conversion_info['scaling']['multiplier'])
         offset = float(conversion_info['scaling']['offset'])
-        unit = self._zip_segment_conversion_unit(conversion_info, version)
+        unit = self._zip_unit(conversion_info['scaling'], version)
         segment[:,channel] = segment[:,channel] * multiplier + offset
         segment.info['columns'][channel] = join_data_label(channel_name, unit)
         return segment
 
-    def _zip_segment_conversion_unit(self, conversion_info, version):
+    def _zip_unit(self, conversion_info, version):
         if version in ['0.%d' % i for i in range(3)]:
-            return conversion_info['scaling']['unit']
+            return conversion_info['unit']
         else:
-            return conversion_info['scaling']['unit']['unit']
+            return conversion_info['unit']['unit']
 
     def _parse_params(self, lines):
         info = {}
-- 
2.26.2