XMM-Newton SAS Home Page
XMM-Newton Science Analysis System

dsslib (dsslib-5.12.2) [xmmsas_20211130_0941-20.0.0]

Data Subspace Expression Parser

Tools are provided for converting a restricted set of selectlib expressions into a data subspace specification (see the selectlib documentation for details of the expression format). A parser reads the selection expression and generates subspace filters and components as appropriate. However, not all selection expressions can be expressed as data subspace specifications. Those types of expressions which cannnot be handled by the parser involve arithmetic operations on column values. Arithmetic expressions of constants are allowed, however.

$\displaystyle RAWX+1 > 50 \qquad \textrm{NOT allowed} $

$\displaystyle RAWY > 50\!*\!*2 \qquad \textrm{allowed} $


XMM-Newton SOC -- 2021-11-30