output calculated background to file

pmetz

Hi All,

In the GUI, STR instances have a menu option "Save if displayed Yobs,Ycalc,Diff,Bkg,Phases." My question is simply, isn't there a keyword to enable output of the calculated background from launch mode?

I note there's some kind of work-around from 2011 in this forum. I don't understand why we should need to run the same script twice with user intervention (toggling booleans) to get the desired output... this seems hacky.

In other words:

macro WriteFit(fname)
{
    xdd_out fname
        load out_record out_fmt out_eqn {
            "%.6f "  = X ;
            "%.6f "  = Yobs ;
            "%.6f "  = Ycalc ;
            "%.6f\n" = Get(bkg) ;  '<--- what goes here?? This writes 0's.
        }
}

xdd ...

   bkg @ 1 1 1  ' <--- Chebyshevv polynomial

   ...

   str
      ...

   WriteFit(MyOutputString.txt)

johnsoevans

I'm not aware that there's a built in way of doing this.

It doesn't really answer your question, but when I've wanted an automatic way of doing this in the past I've written my own simple background function as a fit_obj. Or you could just output the background coefficents (you can give them names) and calculate the background using the appropriate Chebyshev polynomial. You'd need to do a bit of checking to make sure you have the same function/normalisation range as Alan uses.

alancoelho

Version 7 has the Get(bkg) functionality.

For V6 and before then comment out everything else but bkg and then save Ycalc.

metosa35

Dear Alan,

Can you elaborate more on your reply? I have TOPAS 6 commercial and it is not an easy option for now to upgrade to V7. How should I change

macro WriteFit(fname)
{
xdd_out fname
load out_record out_fmt out_eqn {
"%.6f " = X ;
"%.6f " = Yobs ;
"%.6f " = Ycalc ;
"%.6f\n" = Get(bkg) ; '<--- what goes here?? This writes 0's.
}
}

to get background saved into fname? Get(bkg) only generates 0. I tried only "bkg". But it doesn't work.

Thanks

johnsoevans

I don't think this is possible pre-version 7 so you have to use the older inelegant solutions (see also the old thread.

Essentially you comment out your stuctures, hkl_Is, etc (or set their scale to zero) and do zero iterations. What gets calculated is just the background which you can output as Ycalc.

metosa35

Thanks. I got the background I want using "inelegant" solution.