RotateInstrumentComponent v1¶

# Load a MUSR file
musr = Load('MUSR00015189')
# and use the first workspace in the workspace group
ws = mtd['musr_1']

def pos3D_as_str(pos, digits=6):
   """ Produces a string with a V3D position (x, y, z) from a V3D object,
       using a fixed limited number of digits (for robust string comparisons).
   """
   def nz(value):
      """ Handles potential issues with +-0 (for 6 digits text output) """
      return 0.0 if abs(value) < 1e-7 else value

   precision = str(digits)
   format_str = '[{0:.'+precision+'f}, {1:.'+precision+'f}, {2:.'+precision+'f}]'
   result = format_str.format(nz(pos.getX()), nz(pos.getY()), nz(pos.getZ()))
   return result

print('Original positions of detectors 1 and 2')
opos1 = ws.getInstrument().getDetector(1).getPos()
opos2 = ws.getInstrument().getDetector(2).getPos()
print('Det 1: {0}'.format(pos3D_as_str(opos1)))
print('Det 2: {0}'.format(pos3D_as_str(opos2)))

# Rotate bank 'back' around the Z axis by 90
RotateInstrumentComponent( ws, ComponentName='back', X=0,Y=1,Z=0, Angle=90.0 )

print('Positions of detectors 1 and 2 after rotation')
pos1 = ws.getInstrument().getDetector(1).getPos()
pos2 = ws.getInstrument().getDetector(2).getPos()
print('Det 1: {0}'.format(pos3D_as_str(pos1)))
print('Det 2: {0}'.format(pos3D_as_str(pos2)))

# Load a MUSR file
musr = Load('MUSR00015189')
# and use the first workspace in the workspace group
ws = mtd['musr_1']

def pos3D_as_str(pos, digits=6):
   """ Produces a string with a V3D position (x, y, z) from a V3D object,
       using a fixed limited number of digits (for robust string comparisons).
   """
   def nz(value):
      """ Handles potential issues with +-0 (for 6 digits text output) """
      return 0.0 if abs(value) < 1e-7 else value

   precision = str(digits)
   format_str = '[{0:.'+precision+'f}, {1:.'+precision+'f}, {2:.'+precision+'f}]'
   result = format_str.format(nz(pos.getX()), nz(pos.getY()), nz(pos.getZ()))
   return result

print('Original positions of detectors 1 and 4')
opos1 = ws.getInstrument().getDetector(1).getPos()
opos4 = ws.getInstrument().getDetector(4).getPos()
print('Det 1: {0}'.format(pos3D_as_str(opos1)))
print('Det 4: {0}'.format(pos3D_as_str(opos4)))

# Rotate bank 'back' around the Z axis by 3 detectors.
RotateInstrumentComponent( ws, ComponentName='back', X=0,Y=0,Z=1, Angle=3*360.0 / 32 )

print('Positions of detector 1 after rotation')
pos1 = ws.getInstrument().getDetector(1).getPos()
print('Det 1: {0}'.format(pos3D_as_str(pos1)))
print('Detector 1 took place of detector 4')

import numpy as np

# Load a MUSR file
musr = Load('MUSR00015189')
# and use the first workspace in the workspace group
ws = mtd['musr_1']

# Rotating a detector doesn't change its position, just its orientation

# Original position of detector 33
print(ws.getInstrument().getDetector(33).getPos())

# Caclulate the solid angles for all detectors in the instrument
# The result is a single-bin workspace with solid angles for all spectra in ws
saws = SolidAngle( ws )
# Collect the solid angles from the first bin in saws and save them in numpy array.
# Numpy module makes it easy to manipulate arrays
sa1 = np.array( [ saws.readY(i)[0] for i in range(saws.getNumberHistograms()) ] )

# Rotate detector 33 around the Z axis by 90 degrees.
RotateInstrumentComponent( ws, DetectorID=33, X=0,Y=0,Z=1, Angle=90 )

# Check the position of detector 33 stays unchanged
print(ws.getInstrument().getDetector(33).getPos())

# Calculate the solid angles after rotation
saws = SolidAngle( ws )
sa2 = np.array( [ saws.readY(i)[0] for i in range(saws.getNumberHistograms()) ] )

# Take element by element difference of the solid angles
diff = sa2 - sa1
# numpy.set_printoptions is not stable across versions.
# manually print array to ensure consistent display for tests
diff = diff.reshape(8, 8)
diff_as_str = ''
for row in range(8):
    for col in range(8):
        diff_as_str += '{: .5f} '.format(diff[row][col])
    diff_as_str += '\n'
print(diff_as_str)
print('The non-zero difference {:.13f} is due to detector {}'.format(diff[4][0], ws.getDetector(32).getID()))