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Дата изменения: Fri Jan 10 22:39:39 2003
Дата индексирования: Sat Dec 22 08:21:19 2007
Кодировка:

XMM-Newton Science Analysis System


implot (implot-2.5.2) [xmmsas_20030110_1802-5.4.1]

Meta Index / Home Page / Description / Source circle radii.

Style `expr'.

In this style, the radius can be scaled from an arbitrary function of column values in the input source table. This is a two-stage process:

1. The arithmetic expression supplied to the parameter radiusexpression is evaluated to give a proto-radius value.
2. The proto-radius value is passed through the function

   radius = maxradius * max(1 + 0.5 * log10(proto-radius / max(proto-radius)), 0.2)
   

   The result is the radius in image pixels. Here `maxradius' (in image pixels) is supplied via the parameter maxradius.

Some users find this a bit too `foolproof' for complete satisfaction, so (after column arithmetic becomes possible) I may in the future either make it simpler (ie dispense with the second step above altogether) or at least allow the option for WYSIWYG setting of radii.