General operating issues
From Tobyfit
How do I remove a data set I no longer require?
In the "Runs" tab there is a button marked "Clear Data Set" which will remove all references to the currently selected data set. You need to choose the data set to delete first using the "Run No" and "Data Set No" drop down lists. To remove all data sets in the current run use the "Clear Runs" button.
How do I include support subroutines when building new models?
On Linux hosts the build of new models in the models directory is controlled by the Makefile that is included there. By default this just lists the sqw_broad.f, sqw_sharp.f and background.f subroutines. If you wish to add a support subroutine to help define your models you should include it in this directory and add the new name into the Makefile. For example, if a support subroutine called gaussian.f was added to tf_models_user, then the line in the Makefile defining the object files should be updated to read:
OBJS=background.o sqw_broad.o sqw_sharp.o gaussian.o
The windows build script does not use the Makefile and just compiles all the .f files in the directory. However it is best to update the Makefile even if only building on Windows in case a Linux build is required at a later date.
Issues with setting parameter limits
Values of parameters are by default unbounded and can take any value during a least squares fit. By setting non-zero values of the "lower" and "upper" entries for a cleared parameter you can limit the range used in the fit process, which may help make the fit more robust and avoid trying to evaluate the model for non-physical parameters. Note that at present the GUI requires both the lower and upper values to be non-zero (this may change in future). You can not just set one bound. If a bound of zero is required you can use a suitably small value, e.g. 1e-10, instead.
Problems with binding parameters
To bind one parameter to another you must enter the parameter number to bind to and the ratio of binding in the table for the parameter. In addition you must also mark the bound parameter as free, i.e. tick the clear box for it.
Loading and saving TFT files with extended format
The TFT file format is a simple ASCII dump of all the parameters required for a simulation. However it does not include the data used in fitting, such as which parameters are to be varied and any limits or bindings on them. A new extended format has been defined which includes most of these additional values and the GUI now writes this out to any TFT file that it creates. Thus if you have defined remove ranges, limits and bindings on a data set you can use "Save TFT" to create a single TFT file with all this data stored. Loading this TFT file in the GUI will restore all these values. At present the server code does not recognise this additional information and is passed this data in a separate file. This means that a TFT file returned by a fit will not include this extra information. Hence if you want to find out what parameters were varied etc. for a given fit you can go to the fit panel and do "load initial TFT". If you want to see the results of the fit in the GUI, in terms of the parameter values and their errors, "load final TFT" will show these, but not the selection, binding and limit data.
Can I use SSO (STFC's Single Sign-ON) method with Tobyfit
Tobyfit users with Federal logins at RAL can use the STFC implementation of Single Sign On (SSO) to access the machine scarf (but not NGS). However, it still requires access to SRB, which is normally provided by having an NGS account. See SSO with Tobyfit.
