Changing parameters in the Advanced Panel
From Tobyfit
How do I alter parameters related to the spectrometer and or chopper?
Some care is needed in defining parameters in the Advanced Pop-up window, particularly if using an instrument other than HET, MARI or MAPS. Many of the values in this panel will change if you change the selection of spectrometer and/or chopper. Since the list of available choppers is dependent on the selected instrument it is vital that you select the instrument first and then the chopper for the run of interest. Once this is done you can then set any additional parameters of the run such as sample shape and crystal orientation correction. Parameters for one run do not effect any other run, so changes have to be made for each run individually.
When entering parameter values in the advanced pane it is important to press <enter> after the value has been typed for the new value to be accepted. It is also necessary to click OK to actually store the new values. If you click on Cancel, all changes will be lost. The same is true if you kill the window or switch to another run using the run selection box in the Runs tab.
The name of the spectrometer and chopper is set based on certain key parameters of these devices. If you wish to change non-key parameters, e.g. the chopper frequency, this will not alter they type of the chopper or the instrument, as shown by the Spectrometer drop-down list in the Runs tab.
If you do wish to set parameters for a new instrument, e.g. Merlin, then you must change some of the key parameters so that they no longer match one of the standard instruments. When you do this (remembering to type <enter> and click <OK>) the instrument is no longer recognised. The spectrometer type is not updated immediately, but if you switch to another run and back to the current one you will see the spectrometer and chopper drop-down values are empty. This indicates user defined settings of these values.
If you change the spectrometer name back to one of HET/MARI/MAPS, the key parameters will be overwritten with the default values. Job submission and fitting do not require one of the predefined spectrometer or chopper names. To check that a fit has the correct parameter values, you should inspect the output file that is returned by a successful fit. This includes a listing of all the actual values used for each run and is shown in the lower pane of the Fit tab when you select the fit job of interest.
Note that if you select the null value for your spectrometer name a warning message will be given, advising you to use the "Clear current" button instead. This will set all spectrometer and chopper values to zero and the names to null. This may be the best approach if your instrument has few or no values in common with one of the predefined ones.
Why does changing the Mosaic parameter (eta) have no effect on the results?
The eta parameter will only alter the results if you are using the MonteCarlo integration method AND within this method you have selected mc_mosaic=true in the integration methods tab. Also, if you change the value and/or the "clear" status of eta within the advanced pop-up you MUST remember to close the window using the "OK" button, not the cancel button, before you try and do a fit or simulate operation.
