;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;
;*NAME:    
;
;       pro p3d_trace
;
;*VERSION:
;
;       $Id$
;
;*CATEGORY:
;
;       P3d data reduction
;
;*CALLING SEQUENCE:
;
;       p3d_trace,array,traces,const=const,ybin=ybin
;                 spec0=spec0,var_spec0=var_spec0,no_display=no_display
;
;*INPUT:
;
;       array:      raw PMAS exposure
;
;*OUTPUT:
;
;       traces:     tracemask
;
;*PARAMETERS:
;
;*KEYWORDS:
;
;       const:      flag, 0 - tracemask has same xsize as <array> and ysize=256
;                         1 - constant trace values for the whole spectrum
;       ybin:       bin factor for the y-direction.
;                   default: ybin=1, i.e. not binned
;       spec0:      add for the tracing algorithm, 
;                   set the y position of the first spectrum 
;       var_spec0:  if <spec0> is set:
;                   give uncertainty of this spectra position
;       no_display: flag, 0 - results are displayed, 1 - display switched off.
;                   default: no_display=0
;
;*CALLED FUNCTIONS:
;
;*CALLED PROCEDURES:
;
;       findspec        correctpos      mean_smo_small  expand_traces
;       mean_smo_1d     med_smo_1d      mean_smo        med_smo
;
;*PURPOSE:
;
;       PMAS quick tracing. 
;       1. Locate spectra
;       2. Follow spectra in the direction of dispersion (optional)
;       ad 1: Peaks are looked for in several (max. 81) columns 
;             and compared to minimize errors because of noise.
;             The procedure works save for at least 10-20 columns, 
;             better more than 40 columns (depending on SNR).
;            
;*MODIFICATION HISTORY:
;
;       TBE: 16/05/2001 - VERSION 1.0   initial programming   
;   
;          
;*AUTHORS:
;
;       TBE             Thomas Becker   Astrophysikalisches Institut Potsdam
;                                       An der Sternwarte 16
;                                       D-14481 Potsdam
;                                       email: tbecker@aip.de
;                                       Tel. (049) 331/7499 - 414
;
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