There are a couple of problems here. I've expanded a tutorial to
include an example of how to format tiles, links and text dynamically
based on annotation parameters.
http://circos.ca/tutorials/lessons/recipes/data_id/images
First, your use of the 'nr' parameter is not allowed, unless you set
restrict_parameter_names=no
in housekeeping.conf. Unfortunately, there was a bug which prevent
these parameters from being parsed correctly. This is fixed for the
next version. The bug affects only parameters that are not in the
default list of accepted parameters. For now, use the 'id' parameter,
such as
hs10 10 20 id=1.000
Second, I think you want to change the label for individual text
items. To do so, you need a rule that changes the label_size - this is
the only way the parameter will be recalculated for each data point.
Here's an example from the tutorial linked to above
<rule>
importance = 100
condition = 1
label_size = eval(sprintf("%dp",remap_int(_ID_,1,100,12,48)))
</rule>
This will remap the value of the 'id' field (range 1..100) to an
integer range (12..48) and assign it to label_size. The "p" suffix for
the size is required - units of pixels.
I'm going to track down the problem you're seeing, though, which seems
to be caused by setting the label_size globally for the track.
Martin