Merge ea47893 into 51ef67d

concert/devices/base.py

@@ -19,6 +19,7 @@
 import threading
 from logbook import Logger
 from concert.base import Parameterizable, Parameter
+from concert.quantities import q
 
 
 LOG = Logger(__name__)
@@ -70,3 +71,38 @@ def _set_state(self, state):
             self['state'].notify()
         else:
             LOG.warn("State {0} unknown.".format(state))
+
+
+class Calibration(object):
+
+    """Interface to convert between user and device units."""
+
+    def to_user(self, value):
+        """Return *value* in user units."""
+        raise NotImplementedError
+
+    def to_steps(self, value):
+        """Return *value* in device units."""
+        raise NotImplementedError
+
+
+class LinearCalibration(Calibration):
+
+    """A linear calibration maps a number of steps to a real-world unit.
+
+    *steps_per_unit* tells how many steps correspond to some unit,
+    *offset_in_steps* by how many steps the device is away from some zero
+    point.
+    """
+
+    def __init__(self, steps_per_unit, offset_in_steps):
+        super(LinearCalibration, self).__init__()
+        self._steps_per_unit = steps_per_unit
+        self._offset = offset_in_steps
+
+    def to_user(self, value_in_steps):
+        return value_in_steps * q.count / self._steps_per_unit - self._offset
+
+    def to_steps(self, value):
+        res = (value + self._offset) * self._steps_per_unit
+        return res.to_base_units().magnitude

concert/devices/motors/aerotech.py

@@ -1,9 +1,9 @@
 """Aerotech"""
 import time
 from concert.quantities import q
-from concert.devices.motors.base import ContinuousMotor, Motor
 from concert.connections.inet import Aerotech
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
+from concert.devices.motors.base import ContinuousMotor, Motor
 
 
 class Aerorot(ContinuousMotor):

concert/devices/motors/base.py

@@ -18,7 +18,7 @@
 import logbook
 from concert.quantities import q
 from concert.base import HardlimitError
-from concert.devices.base import Device, Parameter
+from concert.devices.base import Device, Parameter, LinearCalibration
 from concert.asynchronous import async
 
 
@@ -29,8 +29,10 @@ class Motor(Device):
 
     """Base class for everything that moves.
 
-    An motor is used with a *calibration* that conforms to the
-    :class:`Calibration` interface to convert between user and device units.
+    A motor is used with a *calibration* that conforms to the
+    :class:`Calibration` interface to convert between user and device units. If
+    *calibration* is not given, a default :py:class:`LinearCalibration` mapping
+    one step to one millimeter with zero offset is assumed.
 
     .. py:attribute:: position
 
@@ -41,15 +43,20 @@ class Motor(Device):
     MOVING = 'moving'
     LIMIT = 'limit'
 
-    def __init__(self, calibration, limiter=None):
+    def __init__(self, calibration=None, limiter=None):
         params = [Parameter('position',
                             self._get_calibrated_position,
                             self._set_calibrated_position,
                             q.m, limiter,
                             "Position of the motor")]
 
         super(Motor, self).__init__(params)
-        self._calibration = calibration
+
+        if not calibration:
+            self._calibration = LinearCalibration(1 * q.count / q.mm, 0 * q.mm)
+        else:
+            self._calibration = calibration
+
         self._states = \
             self._states.union(set([self.STANDBY, self.MOVING, self.LIMIT]))
 

concert/devices/motors/crio.py

@@ -3,8 +3,8 @@
 """
 import readline
 from concert.quantities import q
+from concert.devices.base import LinearCalibration
 from concert.devices.motors.base import Motor
-from concert.devices.calibration import LinearCalibration
 from concert.connections.inet import Connection
 
 

concert/devices/motors/dummy.py

@@ -2,7 +2,7 @@
 import random
 from concert.quantities import q
 from concert.devices.motors import base
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
 
 
 class DummyLimiter(object):
@@ -21,7 +21,7 @@ class Motor(base.Motor):
 
     """Dummy Motor class implementation."""
 
-    def __init__(self, calibration=LinearCalibration(q.count / q.mm, 0 * q.mm),
+    def __init__(self, calibration=None,
                  limiter=None, position=None, hard_limits=None):
         super(Motor, self).__init__(calibration, limiter)
         if hard_limits is None:

concert/tests/integration/processes/test_rotationaxisalignment.py

@@ -5,7 +5,7 @@
 from testfixtures import ShouldRaise
 from concert.quantities import q
 from concert.devices.motors.dummy import Motor
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
 from concert.asynchronous import dispatcher
 from concert.tests import slow
 from concert.processes.tomoalignment import Aligner

concert/tests/integration/processes/test_scan.py

@@ -4,7 +4,6 @@
 from concert.quantities import q
 from testfixtures import compare
 from concert.tests import assert_almost_equal
-from concert.devices.calibration import LinearCalibration
 from concert.devices.motors.dummy import Motor as DummyMotor
 from concert.devices.cameras.dummy import Camera
 from concert.processes.scan import Scanner, StepTomoScanner, ascan, dscan

concert/tests/unit/devices/test_monochromator.py

@@ -4,7 +4,7 @@
 from testfixtures import ShouldRaise
 from concert.tests import assert_almost_equal
 from concert.quantities import q
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
 from concert.devices.monochromators.dummy import\
     Monochromator as DummyMonochromator
 from concert.devices.monochromators import base

concert/tests/unit/devices/test_motor.py

@@ -1,12 +1,36 @@
 import unittest
 import logbook
 from concert.quantities import q
+from concert.devices.base import LinearCalibration
 from concert.devices.motors.base import Motor
-from concert.devices.calibration import LinearCalibration
 from concert.devices.motors.dummy import Motor as DummyMotor,\
     ContinuousMotor as DummyContinuousMotor
 
 
+def test_default_motor_has_default_calibration():
+    class MockMotor(Motor):
+        def __init__(self):
+            self._position = 0
+            super(MockMotor, self).__init__()
+
+        def _set_position(self, position):
+            self._position = position
+
+        def _get_position(self):
+            return self._position
+
+    handler = logbook.TestHandler()
+    handler.push_application()
+
+    motor = MockMotor()
+    motor.move(-1 * q.mm).wait()
+    assert motor.position == -1 * q.mm
+    motor.position = 2.3 * q.mm
+    assert motor.position == 2.3 * q.mm
+
+    handler.pop_application()
+
+
 class TestDummyMotor(unittest.TestCase):
 
     def setUp(self):

concert/tests/unit/measures/test_rotationaxismeasure.py

@@ -5,7 +5,7 @@
 from concert.quantities import q
 from concert.measures.rotationaxis import Ellipse
 from concert.tests.util.rotationaxis import SimulationCamera
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
 from concert.devices.motors.dummy import Motor
 from concert.tests import slow
 from concert.processes.scan import Scanner

concert/tests/unit/test_calibration.py

@@ -1,6 +1,6 @@
 import unittest
 from concert.quantities import q
-from concert.devices.calibration import LinearCalibration
+from concert.devices.base import LinearCalibration
 
 
 class TestLinearCalibration(unittest.TestCase):