XMM-Newton Science Analysis System


implot (implot-2.19) [xmmsas_20141104_1833-14.0.0]

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 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.