Re: plotting XMM RGS data

Hi Juan,


    juan> I'm trying to fit XMM/RGS data and when I try to plot the
    juan> result using rplot_counts, I got a plot where I can see the
    juan> gaps of the response matrix. The plot can be download from
    juan> anonymous ftp at:

One thing I noticed in your script - you have no model defined (or you
just didn't show that).

Suppose you define a model as 

fit_fun( "poly(1)" );
set_par( "poly(1).*", 0 );
eval_counts;

rp( 1 );

Then what happens?


I can't see your files because of some ftp problem (logged in here or
there).  Could you point me to a HEAD network location?

I've seen some bad behavior in in RGS data, which can give Inf or NaN
in residuals.  My ad hoc solution was to ignore the offending
wavelength regions, which was OK because I only had a couple
contiguous regions.

In general if you want some automatic way, you might need to find the
bad regions in the arf (or data or err) and ignore those regions.

 a = get_arf( n_arf );
 l = where( a.value == 0 );

 ignore_list( n_spec, l );

... but I believe that will fail under grouping, if the spectrum has
been rebinned, in which case it is a bit more tedious to find the
corresponding wave_lo, wave_hi to feed to ignore.

So perhaps using the data itself might help.

c = get_data_counts( h_spec );

then maybe

l = where( c.value ==0); 
ignore_list( h_spec, l );


But I'm just guessing, since I cannot reproduce the error I had in the
RGS data I'm currently working on, so I can't diagnose it directly.  I
think anytime you have Inf or NaN, pgplot cannot handle it, so you
need to ignore the regions, or set the scales explicitly (which I
don't think you can control in the rplot residuals pane).

I might need to look at your data, if you don't find a solution.


-- Dave

David Huenemoerder  617-253-4283 (o); -253-8084 (f); http://space.mit.edu/home/dph
MIT Kavli Institute for Astrophysics and Space Research
70 Vassar St., NE80-6065,
Cambridge, MA  02139
[Admin. Asst.: Elaine Tirrell, 617-253-7480, egt_at_email.domain.hidden
----
You received this message because you are
subscribed to the isis-users list.
To unsubscribe, send a message to
isis-users-request_at_email.domain.hiddenwith the first line of the message as:
unsubscribe