XPICKER - X wiggle-trace plot of f(x1,x2) via Bitmap with PICKing	

 xpicker n1= [optional parameters] <binaryfile				

 X Menu functionality:							
    Pick Filename Window	default is pick_file			
    Load		load an existing Pick Filename			
    Save		save to Pick Filename				
    View only/Pick	default is View, click to enable Picking	
    Add/Delete		default is Add, click to delete picks		
    Cross off/on	default is Cross off, click to enable Crosshairs

 In View mode:								
    a or page up keys          enhance clipping by 10%                 
    c or page down keys        reduce clipping by 10%                  
    up,down,left,right keys    move zoom window by half width/height   
    i or +(keypad)             zoom in by factor 2                     
    o or -(keypad)             zoom out by factor 2                    
    l 				lock the zoom while moving the coursor	
    u 				unlock the zoom 			

 Notes:								
	Menu selections and toggles ("clicks") are made with button 1	
	Pick selections are made with button 3				
	Edit a pick selection by dragging it with button 3 down	or	
	by making a new pick on that trace				
	Reaching the window limits while moving within changes the zoom	
	factor in this direction. The use of zoom locking(l) disables it

 Other X Mouse functionality:						
 Mouse Button 1	Zoom with rubberbox				
 Mouse Button 2	Show mouse (x1,x2) coordinates while pressed	

 The following keys are active in View Only mode:			

 Required Parameters:							
 n1=		number of samples in 1st (fast) dimension		

 Optional Parameters:							
 mpicks=pick_file	name of output (input) pick file		
 d1=1.0		sampling interval in 1st dimension		
 f1=d1		  first sample in 1st dimension				
 n2=all		 number of samples in 2nd (slow) dimension	
 d2=1.0		 sampling interval in 2nd dimension		
 f2=d2		  first sample in 2nd dimension				
 x2=f2,f2+d2,...	array of sampled values in 2nd dimension	
 bias=0.0	       data value corresponding to location along axis 2
 perc=100.0	     percentile for determining clip			
 clip=(perc percentile) data values < bias+clip and > bias-clip are clipped
 xcur=1.0	       wiggle excursion in traces corresponding to clip	
 wt=1		   =0 for no wiggle-trace; =1 for wiggle-trace		
 va=1		   =0 for no variable-area; =1 for variable-area fill	
                        =2 for variable area, solid/grey fill          
                        SHADING: 2<=va<=5  va=2 light grey, va=5 black 
 verbose=1	      =1 for info printed on stderr (0 for no info)	
 xbox=50		x in pixels of upper left corner of window	
 ybox=50		y in pixels of upper left corner of window	
 wbox=550	      	width in pixels of window			
 hbox=700		height in pixels of window			
 x1beg=x1min		value at which axis 1 begins			
 x1end=x1max		value at which axis 1 ends			
 d1num=0.0		 numbered tic interval on axis 1 (0.0 for automatic)
 f1num=x1min		first numbered tic on axis 1 (used if d1num not 0.0)
 n1tic=1		number of tics per numbered tic on axis 1	
 grid1=none		grid lines on axis 1 - none, dot, dash, or solid
 label1=		label on axis 1					
 x2beg=x2min		value at which axis 2 begins			
 x2end=x2max		value at which axis 2 ends			
 d2num=0.0		 numbered tic interval on axis 2 (0.0 for automatic)
 f2num=x2min		first numbered tic on axis 2 (used if d2num not 0.0)
 n2tic=1		number of tics per numbered tic on axis 2	
 grid2=none		grid lines on axis 2 - none, dot, dash, or solid 
 label2=		label on axis 2					
 labelfont=Erg14	font name for axes labels			
 title=		title of plot					
 titlefont=Rom22	font name for title				
 labelcolor=blue	color for axes labels				
 titlecolor=red	color for title					
 gridcolor=blue	color for grid lines				
 style=seismic		normal (axis 1 horizontal, axis 2 vertical) or	
 		    	seismic (axis 1 vertical, axis 2 horizontal)	
 endian=		=0 little endian, =1 big endian			
 interp=0		no sinc interpolation				
			=1 perform sinc interpolation			
 x2file=		file of "acceptable" x2 values		
 x1x2=1		save picks in the order (x1,x2) 		
 			=0 save picks in the order (x2,x1) 		

 Notes:								
 Xpicker will try to detect the endian value of the X-display and will	
 set it to the right value. If it gets obviously wrong information the 
 endian value will be set to the endian value of the machine that is	
 given at compile time as the value of CWPENDIAN defined in cwp.h	
 and set via the compile time flag ENDIANFLAG in Makefile.config.	

 The only time that you might want to change the value of the endian   
 variable is if you are viewing traces on a machine with a different   
 byte order than the machine you are creating the traces on AND if for 
 some reason the automaic detection of the display byte order fails.   
 Set endian to that of the machine you	are viewing the traces on.	

 The interp flag is useful for making better quality wiggle trace for	
 making plots from screen dumps. However, this flag assumes that the	
 data are purely oscillatory. This option may not be appropriate for all
 data sets.								

 If the x2file=  option is set, then the values from the specified file
 will define the set of "acceptable" values of x2 for xpicker to	
 output. The format is a single column of ASCII values. The number of  
 specified values is arbitrary.					

 Such a file can be built from an SU data set via:			
     sugethw < sudata key=offset output=geom > x2example 		

 If the value of x2file= is not set, then				
 xpicker will use the values specified via: x2=.,.,.,. or those that are", 
 computed from the values of f2=  and d2= as being the "acceptible
 values.								

 See the selfdoc of  suxpicker  for information on using key fields from
 the SU trace headers directly. 					



 AUTHOR:  Dave Hale, Colorado School of Mines, 08/09/90
 with picking by Wenying Cai of University of Utah.
 Endian stuff by Morten Pedersen and John Stockwell of CWP.
 Interp stuff by Tony Kocurko of Memorial University of Newfoundland
 Modified to include acceptable values by Bill Lutter of the
     Department of Geology, University of Wisconsin 10/96
 MODIFIED:  P. Michaels, Boise State Univeristy  29 December 2000
            Added solid/grey color scheme for peaks/troughs
 
 G.Klein, IFG Kiel University, 2003-09-29, added cursor scrolling and
            interactive change of zoom and clipping.

 NOTES:
 Interactive picker improved to allow x-axis of picks to be
 coordinated with "key=header" parameter set in driver routine
 suxpicker. Multiple picks per trace are now allowed.

  Input:
  The command line of suxpicker is unchanged.  The parameter"key=header"
  set in  suxpicker controls a) trace x-axis  displayed via xpicker and
  b) the header values in the first column of a pick file either read in
     or written out from xpicker c) header values expected in optional file
      or written out from xpicker c) header values expected in optional file
     x2file= which reads into xpicker allowable trace x-axis values.

   a) example command line:  suxpicker key=offset < shot10.plotpik

   b) pick file format:
	x-axis_value_1 time_1
	x-axis_value_2 time_2  
	x-axis_value_3 time_3
	etc.
	x-axis_value_n time_n

	pick file example:
         1000.000000 0.500000
         2000.000000 1.000000
         3000.000000 1.500000
         4000.000000 2.000000
         5000.000000 2.500000

  c)  format of optional file x2file=:
    	   header_value_1
 	   header_value_2
	   etc.
	   header_val_m

       If file "x2file=" exists in directory from which suxpicker is
      invoked, then these trace header x-axis values are the only allowable
      x-axis pick values used in the pick "add" or "delete" menu operation.
      Header values do not need to be sorted or 1 to 1 with input traces.
      Further, pick file x-axis values can be read into xpicker via load
      operation without having to match key_pickx1_val x-axis values and
      can also be rewritten out an output pickfile.  As indicated, only
      the "add" and "delete" pick operations are influenced by existence
       of this file.

      Offset header values for "x2file=" can be generated by the
      command line:

      sugethw < su_segyfile key=offset output=geom >  x2examplefile=

      Output: Only change is in format of pick_file (format described above).
      If x2file= file exists then x-axis value of added picks
      will be forced to nearest allowable trace x-axis value (input values
      of x2file= file). If x2file= is not set, then the values of x2 
      that are either assigned uniformly to the traces via f2 and d2,
      or by the vector of values of x2=.,.,.,.    will be the "acceptable"
      values.

    Strategy:
   a) malloc() and realloc() used to dynamically allocate memory
	  for array of x-axis value read in from optional file
	  x2file=.  This is done in function read_keyval().

	  b) The pick file dimensions are set in main program via malloc()
	  and then initialized (*apick)[i].picked = FALSE) in function
	  init_picks().  The pick file is declared as pick_t **apick, in
	  order to use realloc() as needed in functions load_picks where the
	  pick file is read in and edit_picks where picks are added.  The
	  call to realloc() and further initializing is performed in
	  function realloc_picks().

	  c) If x2file= file exists the mouse derived x-axis value
	  for a pick to be added is checked against allowable x-axis values
	  to find the closest match via function add_pick called from
	  edit_picks.  If the pick is to be deleted, first a search is done
	  to find the closest x-axis value, then the existing pick values
	  are searched to find the closest radial value (x**2 + t**2) via
	  function del_pick() invoked from edit_picks.

	  d) Code modifications are limited to above mentioned functions,
	  except for additional parameters passed to functions edit_picks,
	  load_picks, save_picks, and check_buttons.