Документ взят из кэша поисковой машины. Адрес оригинального документа : http://xmm.vilspa.esa.es/sas/8.0.0/doc/selectlib/node25.html
Дата изменения: Wed Jul 2 00:22:19 2008
Дата индексирования: Fri Sep 5 21:39:37 2008
Кодировка:

XMM-Newton Science Analysis System


selectlib (selectlib-4.69) [xmmsas_20080701_1801-8.0.0]

Meta Index / Home Page / Description / Example expressions

Table column construction

In the following the symbols RAWX, RAWY stand for names of existing columns in the table to be processed:

• sqrt(RAWX**2 + RAWY**2)
  Constructs a new table column with radius values (provided RAWX /RAWY contain Cartesian detection coordinates)

• 100. * sin((TIME-#TIMEZERO)/#PERIOD * 360)
  Construct a ``predicted intensity'' column for a very simple time-variable source

• RAWX + 100
  Construct a new column which contains the RAWX coordinates shifted by 100 pixels