UpdateInstrumentFromFile dialog.
Table of Contents
Updates detector positions initially loaded in from the Instrument Definition File (IDF) with information from the provided file.
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| Workspace | InOut | MatrixWorkspace | Mandatory | The name of the workspace in which to store the imported instrument |
| Filename | Input | string | Mandatory | The filename of the input file. Currently supports RAW, ISIS NeXus, DAT & multi-column (at least 2) ascii files. Allowed extensions: [‘.raw’, ‘.nxs’, ‘.s*’] |
| MoveMonitors | Input | boolean | False | If true the positions of any detectors marked as monitors in the IDF will be moved also |
| IgnorePhi | Input | boolean | False | If true the phi values form the file will be ignored |
| AsciiHeader | Input | string | If the file is a simple text file, then this property is used todefine the values in each column of the file. For example: spectrum,theta,t0,-,RKeywords=spectrum,ID,R,theta,phi. A dash means skip column. Keywords are recognisedas identifying components to move to new positions. Any other names in the listare added as instrument parameters. | |
| SkipFirstNLines | Input | number | 0 | If the file is ASCII, then skip this number of lines at the start of the file |
Some instrument definition file (IDF) positions are only approximately correct and the true positions are located within data files. This algorithm reads the detector positioning from the supplied file and updates the instrument accordingly. It currently supports ISIS Raw, ISIS NeXus files and ASCII files.
It is assumed that the positions specified in the file are all with respect to the a coordinate system defined with its origin at the sample position. Note that this algorithm moves the detectors without subsequent rotation, hence this means that detectors may not for example face the sample perfectly after this algorithm has been applied.
The ASCII format allows a multi-column text file to provide new positions along with additional parameters for each detector. If a text file is used then the AsciiHeader parameter is required as it identifies each column in the file as header information in the file is always ignored. There is a minor restriction in that the first column is expected to specify either a detector ID or a spectrum number and will never be interpreted as anything else.
The keywords recognised by the algorithm to pick out detector position values & spectrum/ID values are: spectrum, ID, R,theta, phi. The spectrum/ID keywords can only be used in the first column. A dash (-) is used to ignore a column.
As an example the following header:
spectrum,theta,-,-,R
and the following text file:
1 0.0000 -4.2508 11.0550 -2.4594
2 0.0000 0.0000 11.0550 2.3800
3 130.4653 -0.4157 11.0050 0.6708
4 131.9319 -0.5338 11.0050 0.6545
5 133.0559 -0.3362 11.0050 0.6345
would tell the algorithm to interpret the columns as:
Example - Update Instrument:
import math
import os
# priting procedure
def print_10_detectors(instr_type,instr):
''' print first 10 detectors from given instrument '''
# get first 10 detectors using detector ID
print "{0} {1} instrument".format(instr_type, instr.getName())
for i in xrange(0,10):
if i<3:
detBase = 1
else:
detBase = 1101-3
detID = detBase+i
det1 = instr.getDetector(detID);
pos = det1.getPos();
print 'det with ID: {0:5} is monitor? {1:5}, polar angle: {2:10.3f}, position: | {3:<10.3f} | {4:<10.3f} | {5:<10.3f}|\n'.format(\
detID,det1.isMonitor(),(det1.getPhi()*(180/math.pi)),pos.X(),pos.Y(),pos.Z()),
print '*********************************************************************************'
#--------------------------------------------------------------------------------------
# create sample workspace
ws=CreateSampleWorkspace();
#--------------------------------------------------------------------------------------
# load MARI
det=LoadInstrument(ws,InstrumentName='MARI', RewriteSpectraMap=True)
inst1=ws.getInstrument();
#
print_10_detectors('unCalibrated',inst1);
#--------------------------------------------------------------------------------------
# Prepare calibration file changing first 6 detectors & monitors
file_name = os.path.join(config["defaultsave.directory"], "TestCalibration.dat")
f = open(file_name,'w');
# prepare through each spectra in the test workspace and change its detector calibration parameters
f.write(' Test calibration file \n')
f.write(' detID theta delay source_dist detector_dist\n')
for i in xrange(0,6):
f.write('{0} {1} {2} {3} {4} {5}\n'.format(i+1,(i+1)*3.1415926/200,0.5,100,(i+1)*3.1415926/5,10))
f.close();
#--------------------------------------------------------------------------------------
# CALIBRATE:
UpdateInstrumentFromFile(ws,Filename=file_name,AsciiHeader='spectrum,theta,-,-,phi,R',MoveMonitors=True,SkipFirstNLines=2)
inst1=ws.getInstrument();
#--------------------------------------------------------------------------------------
# look at the result:
print_10_detectors('Calibrated',inst1);
Output:
unCalibrated MARI instrument
det with ID: 1 is monitor? 1, polar angle: 0.000, position: | 0.000 | 0.000 | -4.739 |
det with ID: 2 is monitor? 1, polar angle: 0.000, position: | 0.000 | 0.000 | -1.442 |
det with ID: 3 is monitor? 1, polar angle: 0.000, position: | 0.000 | 0.000 | 5.820 |
det with ID: 1101 is monitor? 0, polar angle: -68.640, position: | 0.347 | -0.888 | 3.907 |
det with ID: 1102 is monitor? 0, polar angle: -69.300, position: | 0.347 | -0.919 | 3.900 |
det with ID: 1103 is monitor? 0, polar angle: -69.920, position: | 0.347 | -0.950 | 3.893 |
det with ID: 1104 is monitor? 0, polar angle: -70.510, position: | 0.347 | -0.981 | 3.885 |
det with ID: 1105 is monitor? 0, polar angle: -71.060, position: | 0.347 | -1.012 | 3.877 |
det with ID: 1106 is monitor? 0, polar angle: -71.570, position: | 0.347 | -1.043 | 3.869 |
det with ID: 1107 is monitor? 0, polar angle: -72.060, position: | 0.347 | -1.073 | 3.861 |
*********************************************************************************
Calibrated MARI instrument
det with ID: 1 is monitor? 1, polar angle: 0.628, position: | 0.003 | 0.000 | 10.000 |
det with ID: 2 is monitor? 1, polar angle: 1.257, position: | 0.005 | 0.000 | 10.000 |
det with ID: 3 is monitor? 1, polar angle: 1.885, position: | 0.008 | 0.000 | 10.000 |
det with ID: 1101 is monitor? 0, polar angle: 2.513, position: | 0.011 | 0.000 | 10.000 |
det with ID: 1102 is monitor? 0, polar angle: 3.142, position: | 0.014 | 0.001 | 10.000 |
det with ID: 1103 is monitor? 0, polar angle: 3.770, position: | 0.016 | 0.001 | 10.000 |
det with ID: 1104 is monitor? 0, polar angle: -70.510, position: | 0.347 | -0.981 | 3.885 |
det with ID: 1105 is monitor? 0, polar angle: -71.060, position: | 0.347 | -1.012 | 3.877 |
det with ID: 1106 is monitor? 0, polar angle: -71.570, position: | 0.347 | -1.043 | 3.869 |
det with ID: 1107 is monitor? 0, polar angle: -72.060, position: | 0.347 | -1.073 | 3.861 |
*********************************************************************************
Categories: Algorithms | DataHandling\Instrument | DataHandling\Raw