James Tappin
This document is intended to collect together a quick guide on how to perform certain operations which are non-obvious. It is not comprehensive. If you think of something that needs describing and that you think will be useful for others, please let me know.
If you have a dataset and want another one with similar channels etc. then the easiest way to do this is to save the dataset to a file (e.g. tmp.sav) and then restore it. If you don't need to keep the channel list, then you can just create a new dataset while the previous one is the currently selected dataset and most other properties will be inherited.
When adding to data search paths, the chooser menu produced by the picker is initialized to the currently selected path, or to the current directory if no path has been selected. So if you want to add a subdirectory (or a sibling) of a directory that is already in the path, then click on that directory before clicking on ``Pick''. Equally if you want to add a subdirectory of the current directory, then make sure no paths are selected.
Sometimes if you make an action that will produce a modal widget (e.g. a file selector) and then click on another button before that widget has appeared, this will lock up IDL (and temporarily the window manager) and cause it to crash out to the shell prompt. I do not know if this is a problem in IDL or in Motif, but it's not something that can be resolved by IDL_HS. The only work around is to take care to wait for widgets to appear (unless you know that the widget being created is not modal).
At present the selection of track maps is manual. The recommended maps are:
To select several channels from the same group, there are two options:
In spect datasets, when there is only a single channel group on each panel, then the different sectors are given different colours, however for datasets where there are several channel groups on one or more panels, then the colours are used for the channel groups and sectoring is only useful to show the spread.
In PAD datasets, long averaging intervals can produce misleading results if the magnetic field changes significantly during the averaging interval. Better is either (if the fluxes are high enough) to use a spacing setting to only show every spin, or to select the shortest averaging time that will give reasonable statistics and a longer spacing (e.g. 5 minute averages calculated once per hour).
Since generating the stream list for a PAD dataset may involve a large number of mouse clicks (unfortunately the stream combinations typically used mean that multiple selection is not practical), it is possible to save stream selection lists and then restore them to another dataset.
If you are combining 4 & 8 sector streams in the same panel of a PAD dataset, it is usually best to put the 8-sector stream first so that its sectors are denoted by numbers.
The ULEIS data that are used by IDL_HS do not have merged magnetic fields. Therefore, field data must be provided from an external source, the default is to use the mag files from FunTech which have just a date, the 3 components (in spacecraft coordinates) and the total field. If you need to use ACE mag data from other sources, then you will need to modify the UMAG_ACE.SPEC file in the Data/specfiles directory of the distribution. The field files need to be in the UDS search path (not the ULEIS search path) as the reading uses the same routines as for UDS rate datasets.
If you have a current dataset, then the intial search in the ``Examine file'' selector is restricted to the time range of that dataset. This can save a lot of time in searching for the correct file to examine (especially if you are after ula files!).
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The translation was initiated by James Tappin on 2002-03-04