Johan Bregeon / gammalib

…el_grad and GObservation::npred_grad to 0.0002.

This value is equivalent to 1 arcsec for angular parameters, and improves the precision of the position determination.

This has been done by adding a new member m_instrument that contains the instrument name. Seeds have been added to the observations registry for HESS, MAGIC and VERITAS, and the instrument name is now extracted from the XML file. This allows using the GCTA... classes for other instruments, using the appropriate instrument names.

This is needed to support the preliminary MAGIC data response format.

GCTAModelRadialAcceptance::eval,
GCTAModelRadialAcceptance::eval_gradients,
GCTAModelRadialAcceptance::npred, and
 GCTAModelRadialAcceptance::mc methods.

…his allows taking into account the deadtime correction in the GCTAResponse::mc method.

…DEADC keyword is not set correctly in the actual event lists)