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XMM-Newton Science Analysis System

xmmselect (xmmselect-2.67) [xmmsas_20211130_0941-20.0.0]

Task invocation and GUI initialization

xmmselect must be invoked with the name of a table in an existing data set via the task parameter table. This specified table is first inspected for names, types and numerical limits of existing columns and a list of corresponding pushable buttons with associated check buttons is displayed within the main window.

During the initial scan it is also checked whether or not the table comprises DSS (Data SubSpace) information, i.e., if it has been filtered in a previous xmmselect or evselect run. The DSS formalism is a means to store the selection history of a table in a systematic and easily accessible form. For more details on this please consult the documentation of package dsslib.

If DSS information has been found the following dialog box is presented right after the display of the main window:


Figure: Dialog signaling presence of DSS information in input table

Ending the dialog with Yes will convert the DSS specification into a selection expression and present this in an editable field in a new dedicated dialog:


Figure: Dialog to import expression
From there it can be imported into the selection expression widget of the main window with the buttons Import (AND) or Import (OR). The difference between the two import methods is not relevant in this context and will be described later. Pushing the Cancel button will end the dialog disregarding the DSS specification. Please note: If DSS information is present it is very likely that the table has been filtered with the corresponding expression already. Importing the expression and re-doing the filtering will, thus, have no effect. In this regard the DSS import is to be regarded as an informative aid for inquiring the table's selection history.

XMM-Newton SOC -- 2021-11-30