suximage.su.graphics.xplot

su 的源代码库

 SUXIMAGE - X-windows IMAGE plot of a segy data set	                

 suximage infile= [optional parameters] | ...  (direct I/O)            
  or					                		
 suximage <stdin [optional parameters] | ...	(sequential I/O)        

 Optional parameters:						 	

 infile=NULL SU data to be ploted, default stdin with sequential access
             if 'infile' provided, su data read by (fast) direct access

	      with ftr,dtr and n2 suximage will pass a subset of data   
	      to the plotting program-ximage:                           
 ftr=1       First trace to be plotted                                 
 dtr=1       Trace increment to be plotted                             
 n2=tr.ntr   (Max) number of traces to be plotted (ntr is an alias for n2)
	      Priority: first try to read from parameter line;		
		        if not provided, check trace header tr.ntr;     
		        if still not provided, figure it out using ftello

 d1=tr.d1 or tr.dt/10^6	sampling interval in the fast dimension	
   =.004 for seismic 		(if not set)				
   =1.0 for nonseismic		(if not set)				

 d2=tr.d2		sampling interval in the slow dimension	        
   =1.0 		(if not set or was set to 0)		        

 key=			key for annotating d2 (slow dimension)		
 			If annotation is not at proper increment, try	
 			setting d2; only first trace's key value is read

 f1=tr.f1 or tr.delrt/10^3 or 0.0  first sample in the fast dimension	

 f2=tr.f2 or tr.tracr or tr.tracl  first sample in the slow dimension	
   =1.0 for seismic		    (if not set)			
   =d2 for nonseismic		    (if not set)			

 verbose=0             =1 to print some useful information		

 tmpdir=	 	if non-empty, use the value as a directory path	
		 	prefix for storing temporary files; else if the	
	         	the CWP_TMPDIR environment variable is set use	
	         	its value for the path; else use tmpfile()	

 Note that for seismic time domain data, the "fast dimension" is	
 time and the "slow dimension" is usually trace number or range.	
 Also note that "foreign" data tapes may have something unexpected	
 in the d2,f2 fields, use segyclean to clear these if you can afford	
 the processing time or use d2= f2= to override the header values if	
 not.									

 See the ximage selfdoc for the remaining parameters.		        


 Credits:

	CWP: Dave Hale and Zhiming Li (ximage, etc.)
	   Jack Cohen and John Stockwell (suximage, etc.)
	MTU: David Forel, June 2004, added key for annotating d2
      ConocoPhillips: Zhaobo Meng, Dec 2004, added direct I/O

 Notes:

      When provide ftr and dtr and infile, suximage can be used to plot 
      multi-dimensional volumes efficiently.  For example, for a Offset-CDP
      dataset with 32 offsets, the command line
      suximage infile=volume3d.su ftr=1 dtr=32 ... &
      will display the zero-offset common offset data with ranrom access.  
      It is highly recommend to use infile= to view large datasets, since
      using stdin only allows sequential access, which is very slow for 
      large datasets.

	When the number of traces isn't known, we need to count
	the traces for ximage.  You can make this value "known"
	either by getparring n2 or by having the ntr field set
	in the trace header.  A getparred value takes precedence
	over the value in the trace header.

	When we must compute ntr, we don't allocate a 2-d array,
	but just content ourselves with copying trace by trace from
	the data "file" to the pipe into the plotting program.
	Although we could use tr.data, we allocate a trace buffer
	for code clarity.