XMM-Newton Science Analysis System


selectlib (selectlib-4.77) [xmmsas_20230412_1735-21.0.0]

File-based filters

There are three special file-based filters which perform filtering with Good Time Intervals, spatial image masks, and region tables. The syntax is:

gti(blockspec,Tcolumn)

   mask(blockspec,Xoffset,Yoffset,Xcolumn,Ycolumn)

   region(blockspec,Xcolumn,Ycolumn) or region(blockspec)

with

Tcolumn 		 : the time value to be checked; usually a column name

Xoffset,Yoffset 		 : a vector by which the image mask is to beshifted

Xcolumn,Ycolumn 		 : coordinates of point to test - usually givenas column names

blockspec is a block specifier which must point to a GTI table, a mask image, or a region table respectively. It must be in either of the four forms setname, setname+blockid, setname[blockid], or setname:blockid where setname must be the name of an existing data set and blockid an identifier of a block in that data set. If the first form, setname, is used, the filter data are sought in the first block of the named data set. For the latter three forms, the data set name is optional. If omitted, it refers to the data set of the currently processed table. blockid can either be an identifier starting with a letter which must then be the name of a block in the specified data set or a simple number which is directly interpreted as a block sequence number (starting from 1).