; NAME:
;      BADPIXVAL
;
; PURPOSE: 
;      Returns a bad pixel frames with bad pixels having nonzero values
;
; CALLING SEQUENCE:
;      Result = BADPIXVAL (badmask, maxval)
;
; INPUTS:
;      Badmask = The bad pixel mask
;      Maxval =  The maxium value to use for bad pixel values
;
; OUTPUT:
;      Returns a frame with bad pixel values calculated by raising the
;      maxval to a uniform random power between 0 and 1, or a very low val
;      
; PROCEDURE:
;      Get the locations of the bad pixel values, chose a set fraction
;      of them to be low values, and return a frame with low values
;      set to 0, and high values linearly distributed
;      less than maxval
;
; MODIFICATION HISTORY:
;      created Jun 14 2003 by John Dermody

function badpixval, badmask, maxval

; make bad pixels
badframe = 1. - float(badmask)

badloc = where(badframe eq 1)
if (badloc eq [-1]) then return, badframe

nbad = (size(badloc))[1]
badframe[badloc] = randomu(seed, nbad)

; frequency of lows
flow = 0.25

lowloc = where(badframe[badloc] lt flow)
if (lowloc ne [-1]) then lowloc = badloc[lowloc]
nlow = (size(lowloc))[1]

highloc = where(badframe[badloc] gt flow)
if (highloc ne [-1]) then highloc = badloc[highloc]
nhigh = (size(highloc))[1]

; dead pixels
if (nlow ne 0) then begin
  badframe[lowloc] = 0.
endif

; gauss related to rdnoise
if (nhigh ne 0) then begin
  badframe[highloc] = maxval * (randomu(seed, nhigh))
endif

return, badframe
end