>>vpfit

 VPFIT 2.02DR

 maximum file size      :   100000
 maximum chunk size     :   10000
 maximum no. parameters :   528
 maximum no. chunks     :   16
 exceeding above will corrupt results probably without warning
 

  vacuum wavelengths assumed
  Using data from : /home/rfc/atom.dat

  *****************************************
  * ALL SIGMAS MULTIPLIED BY    1.50000   *
  * SEE VP_SETUP.DAT FILE                 *
  *****************************************
 

  options:   <CR> for previous value
  I - interactive setup and fit
  F - run from an input file
  D - display profiles from input file
  ? for help
  option (key) (key)...
> I ad il   <-- Note the extra parameters here.

 Add lines if prob(tot) < 0.0100   or prob(KS) < 0.0100  [the 'ad' does this]
 Removes ill-conditioned lines               [from the 'il']
  lower case characters following values are treated as labels.  if the same
  upper case character follows another value then it will be tied to the lower
  case label.  isolated (un-paired) upper case characters fix values.

  setup: ? help, <CR> defaults, n,z,b,cs,sf,il,w,me,p,d,v to change
>

 Column density (n), logN (l) or emission (e), scalefactor
>
  Filename   1 or ? (lam,n) [     ]:
> q2233
  IRAF v2.10 wavelength coefficients
  Data is subset of larger one, wavelengths
   shifted by LTV1 =  -9624 channels
  sigma scale (midpoint value) :    1.50000
 Plot? [y]
>
 at co   co   3
 at er   co   2
 at ti   co   5
 plot parameter? (type he for options list)
>

 PGPLOT device? (? for list)
> /xw
 Expand plot if needed:
 Cursor ("e" to mark edges, "q" when OK)
 Cursor ("e" to mark edges, "q" when OK)
  Channel  13161
 right edge..
  Channel  13979
 Cursor ("e" to mark edges, "q" when OK)
 Mark region in which data is to be fitted:
 left limit (space when ready)
 right limit
 Region limits:  3822.532A (channel 13370) -   3827.500A ( 13623)
  Channels   13370  13623
  Vacuum wavelength for start of chunk is     3822.54
 FWHM : 0.073A
  Line   1 :ion, lamda0, N,b,z? <CR> to end
  .. in the graphics window
HI
 Wavelength used:    1215.67
 set cursor x- wavelength, y- base of feature
  .. and now half width at half (optical) depth
  Estimated vac wavelength & z are    3825.37    2.14682
     13.6449    52.15    2.14682
  Line   2 :ion, lamda0, N,b,z? <CR> to end
  .. in the graphics window
HI 1215 13.1793 18.99 2.145653   <-- You can enter all parameters if you want to
  Wavelength used:    1215.67
  Line   3 :ion, lamda0, N,b,z? <CR> to end
  .. in the graphics window

  Include other data? y, n (def),
 (or sf for more from the same file)
>
 

  Continue (c), fit (f), or stop (s)? [f]
>

  no. of ions for fitting is   2
 

   ion          N           z           b         bturb   temp

 iteration   :   0 ( 1 )
 chi-squared :        2.482 (   546.0855,  220 )

   H I       13.6449    2.146822      52.15       0.00   0.00E+00  0    !  1
   H I       13.1793    2.145653      18.99       0.00   0.00E+00  0    !  2

 iteration   :   1 ( 1 )
 chi-squared :        2.481 (   545.8601,  220 )

   H I       13.6491    2.146824      52.79       0.00   0.00E+00  0    !  1
   H I       13.1822    2.145652      19.06       0.00   0.00E+00  0    !  2

 parameter errors:
   H I        0.0270    0.000028       3.69                             !  1
   H I        0.0487    0.000018       2.43                             !  2

 statistics for whole fit:
  Runs test  K-S test Chi-squared  Chans ndf   APr   Xp(.68) Xp(.95) Xp(.99)
   0.00000   0.00009    545.86     226  220   0.000  229.46  255.32  271.03

 statistics for each region :
    Start      End    Chi-squared  Chans df?
   3822.32   3827.70    545.86     226  219   0.000 < Prob < 0.000 g= 0.000   1
   3822.30   maxdev       4.6343              0.000   0.956   1.358   1.627
 
 

  Worst region is:  1

   WLM:    3826.92 EW:    8.54071E-02

 Try adding H I     1215.67 at z= 2.1479948 b= 19.2 logN=  12.71

  All old lines lost

  no. of ions for fitting is   3
 

   ion          N           z           b         bturb   temp

 iteration   :   0 ( 2 )
 chi-squared :        1.964 (   426.2586,  217 )

   H I       13.6491    2.146824      52.79       0.00   0.00E+00  0    !  1
   H I       13.1822    2.145652      19.06       0.00   0.00E+00  0    !  2
   H I       12.7086    2.147995      19.21       0.00   0.00E+00  0    !  3
 

.. etc etc, adding HI until the fit is satisfactory, so in this case you wind up with..
 

 iteration   :   9 ( 3 )
 chi-squared :        0.975 (   208.7484,  214 )

   H I       13.5200    2.146694      30.16       0.00   0.00E+00  0    !  1
   H I       13.2090    2.145662      20.62       0.00   0.00E+00  0    !  2
   H I       12.8347    2.148011      29.56       0.00   0.00E+00  0    !  3
   H I       12.9802    2.147318      16.34       0.00   0.00E+00  0    !  4

 iteration   :  10 ( 3 )
 chi-squared :        0.975 (   208.6239,  214 )

   H I       13.5206    2.146695      30.26       0.00   0.00E+00  0    !  1
   H I       13.2089    2.145662      20.62       0.00   0.00E+00  0    !  2
   H I       12.8377    2.148015      29.15       0.00   0.00E+00  0    !  3
   H I       12.9782    2.147318      16.12       0.00   0.00E+00  0    !  4

 parameter errors:
   H I        0.0211    0.000013       1.78                             !  1
   H I        0.0284    0.000012       1.53                             !  2
   H I        0.0695    0.000039       5.94                             !  3
   H I        0.0531    0.000016       2.28                             !  4

 statistics for whole fit:
  Runs test  K-S test Chi-squared  Chans ndf   APr   Xp(.68) Xp(.95) Xp(.99)
   0.00000   0.65614    208.62     226  214   0.591  223.32  248.85  264.36

 statistics for each region :
    Start      End    Chi-squared  Chans df?
   3822.32   3827.70    208.62     226  213   0.533 < Prob < 0.790 g= 0.572   1
   3822.30   maxdev       0.7229              0.673   0.956   1.358   1.627

  Plot? y,n, or c=change device [y]
> y
  Line, system number: (* for internal guesses)
> *
 at co   co   3
 at er   co   2
 at ti   co   5
 plot parameter? (type he for options list)
>

 PGPLOT device? (? for list)
> xw
  Plot? y,n, or c=change device [y]
> n
  Restore continuum? [n]
>
  Fit more lines? [n]
>
[exits]