boot

command list , class list , introduction .
 BOOT N1 N2 N3 NCOPY SEED SET -- Copies a series of spectra, NCOPY times, 
                             changes error bars to simulate bootstrap
                             selection of data points. Spectra can then
                             be used in a fit to generate error bars.

 Parameters: 
     
  N1    -- Slot number of first spectrum to copy
  N2    -- Slot number of last spectrum to copy
  N3    -- First slot for copies
  NCOPY -- Number of copies.
  SEED  -- Seed integer for random number generator
           Enter 0 to carry on from old value.
  SET   -- Apply a mask

 The bootstrap only operates on unmasked data and data with positive 
 error bars. If there are N valid points then N points are sampled
 with replacement to work out how many times each new point will be
 included in bootstrap analysis. If a point is not selected at all
 then its error bar is made negative, otherwise the error bar is
 divided by the square root of the number of times a point was picked.
 With Chi**2 type weights, then the point is effectively used that number
 of times in a fit.

 Associated routines: noise, copy

This command belongs to the classes: fudging .


Tom Marsh, trm@astro.soton.ac.uk, Tue Oct 27 08:56:34 1998 .