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XMM-Newton Science Analysis System


selectlib (selectlib-4.69) [xmmsas_20080701_1801-8.0.0]

Meta Index / Home Page / Description / Arithmetic constants and identifiers

Identifiers

Identifiers are alphanumeric strings which can contain letters, digits and the underscore character (_). They must start with a letter -- case is significant. An identifier must match a name of an existing column in the input table unless it is prefixed by a hash mark (#). In this case it must match any of the above names for symbolic constants or is otherwise interpreted as a reference to a to numerical or textual attribute in the currently processed table. The identifier #ROW has a special meaning: It stands for the current row number (starting from one) in the processed table.

Examples: #PI (the numerical value of $\pi$), #ROW (the current row number), ROWPI (a table column with name ROWPI), #ROWPI (value of the numerical attribute ROWPI).