qmanual.txt

Hi Andy,

At last - a test version of binning into Q-space is ready. Extra command line possibilities are:

 units=Q        
  ... converts to Q=4*pi*sin(theta)/wavelength
      output filename extension is .qye for id31sum
      output filename extensions are .inq where .inp for id31sumall

 units=Q2       
  ... converts to signed Q*Q
      B-factor is linear in this versus log intensity
      output filename extension is .q2
      output filename extensions are .inq2 where .inp for id31sumall

 wvln=0.4124
  ... sets the wavelength in case it is not found in the specfile

Your temp.res file needs to fix any zero shifts.

The programs look for "#Q" in the header expecting Q["3"] to be set as the wavelength in the spec session. Maybe Alejandro can help - I tried to follow what is described at:
   http://www.certif.com/spec_manual/fourc_4_9.html

Only id31sumall and id31sum should be affected. They will attempt to convert the stepsize, hightth and lowtth to the right output unit for you. The step size in Q is based on rounding what you'd get at 30 degrees in twotheta. Excluded regions should remain in two theta units. I have put executables in coral:~/wright/bin and also on diffract31:~/bin. In case of problems the last versions you had should be saved in a tar file in diffract31's bin directory. 

It should be relatively easy to add any other functions of two theta now that these ones are in place. Source is at:

http://fable.svn.sourceforge.net/viewvc/fable/id31sum/trunk/binit.w?view=log

Seems straightfoward to compile for windows too if someone needs it. Let me know if I missed a factor of pi somewhere or if there are some other, more interesting units to supply. Interesting, but so far unjustifiable, would be regular steps in:
  log(Q*Q + c)
... where c is a small constant to avoid taking log(0). D-spacings behave badly near zero in twotheta and looked to be messy.

Enjoy, and let me know if there seem to be any problems. 

Jon