Science Tools Update, August 10, 2006

Science Tools Working Group

We met this week and most probably will meet again in 2 weeks, sharing the time slot with the Catalog group.

The current version of the Science Tools remains v7r4.

Data products: David pointed out that DATE-OBS and DATE-END (the human-readable start and stop times for the data in the file) in the FT1 files should be expressed in TT to be in conformance with FITS specifications. This is not a big change; none of the science tools interpret the date strings to find out times.

Databases and related utilities

No news.

Likelihood analysis

Jim reports that with Sabrina Casanova (LANL) some progress has been made on getting the EGRET response functions in shape to analyze EGRET data with the science tools, but a return visit from Sabrina probably will be needed. EGRET analysis will require something like an extended FT2 file that tallies the mode changes of the trigger telescopes. From a science tools perspective, most of the change is making irfInterface accept time as a parameter, and this capability may be useful to have ready anyway for LAT data analysis.

James and Analia have done some more work on implementing a 'badness of fit' indicator for gtlikelihood. They have been leaning toward flagging bins (energy ranges) where the deviation of the fit is greater than 2sigma from the data. James agreed to circulate a note about the options that they have considered. Intrinsically, likelihood analysis does not provide a goodness of fit, and certainly having an indication whether a given model just isn't working would be worthwhile.

James and Analia are continuing to work on the plotting in likelihood, most recently getting likelihood to set colors in the plots.

GRB tools

No news and I'm afraid still no update on the IRF normalization/gtrspgen issue reported by James a couple of weeks ago; I forgot to ask James at the meeting.

Pulsar tools

James and Masa report that they are commencing work on incorporating the MJDREF change in the pulsar tools. Most of the tools were not paying attention to the value of MJDREF at all - and so did not care when the definition changed. Now they will all read MJDREFI/MJDREFF. The most intricate work has been in making updated test data sets for gtpsearch. The MJDREF-related changes to the tools are expected to take a week or so - possibly longer than the next tag of science tools.

Over the next month or so (until the end of the current build cycle) Masa and James will continue to implement the changes to the interfaces to the science tools to allow multiple systems of time to be specified. This seems to be going well, although James mentioned a couple of bugs in the Windows versions that need to be tracked down.

Observation simulation

No news

User interface and infrastructure