function wigb (a,scal,x,z,amx)%WIGB: Plot seismic data using wiggles.%%  WIGB(a,scal,x,z,amx) %%  IN    a:     seismic data%        scale: multiple data by scale%        x:     x-axis;%        z:     vertical axis (time or depth)%%	 If only 'a' is enter, 'scal,x,z,amn,amx' are decided automatically; %	 otherwise, 'scal' is a scalar; 'x, z' are vectors for annotation in %	 offset and time, amx are the amplitude range.%%%  Author(s): Xingong Li (Exxon-Mobil)%  Copyright 1998-2003 Xingong %  Revision: 1.2  Date: Dec/2002 %  %  Signal Analysis and Imaging Group (SAIG)%  Department of Physics, UofA%if nargin == 0, nx=10;nz=10; a = rand(nz,nx)-0.5; end;[nz,nx]=size(a);trmx= max(abs(a));if (nargin <= 4); amx=mean(trmx);  end;if (nargin <= 2); x=[1:nx]; z=[1:nz]; end;if (nargin <= 1); scal =1; end;if nx <= 1; disp(' ERR:PlotWig: nx has to be more than 1');return;end; % take the average as dx	dx1 = abs(x(2:nx)-x(1:nx-1)); 	dx = median(dx1); dz=z(2)-z(1); xmx=max(max(a)); xmn=min(min(a));  if scal == 0; scal=1; end; a = a * dx /amx;  a = a * scal; fprintf(' PlotWig: data range [%f, %f], plotted max %f \n',xmn,xmx,amx); % set display range x1=min(x)-2.0*dx; x2=max(x)+2.0*dx;z1=min(z)-dz; z2=max(z)+dz; set(gca,'NextPlot','add','Box','on', ...  'XLim', [x1 x2], ...  'YDir','reverse', ...  'YLim',[z1 z2]); 	fillcolor = [0 0 0];	linecolor = [0 0 0];	linewidth = 0.1;	z=z'; 	% input as row vector	zstart=z(1);	zend  =z(nz);for i=1:nx,     if trmx(i) ~= 0;    % skip the zero traces	tr=a(:,i); 	% --- one scale for all section  	s = sign(tr) ;  	i1= find( s(1:nz-1) ~= s(2:nz) );	% zero crossing points	npos = length(i1);	%12/7/97 	zadd = i1 + tr(i1) ./ (tr(i1) - tr(i1+1)); %locations with 0 amplitudes	aadd = zeros(size(zadd));	[zpos,vpos] = find(tr >0);	[zz,iz] = sort([zpos; zadd]); 	% indices of zero point plus positives	aa = [tr(zpos); aadd];	aa = aa(iz);	% be careful at the ends		if tr(1)>0, 	a0=0; z0=1.00;		else, 		a0=0; z0=zadd(1);		end;		if tr(nz)>0, 	a1=0; z1=nz; 		else, 		a1=0; z1=max(zadd);		end;				zz = [z0; zz; z1; z0]; 	aa = [a0; aa; a1; a0];			zzz = zstart + zz*dz -dz;	patch( aa+x(i) , zzz,  fillcolor);	line( 'Color',[1 1 1],'EraseMode','background',  ...         'Xdata', x(i)+[0 0], 'Ydata',[zstart zend]); % remove zero line%'LineWidth',linewidth, ...%12/7/97 'Xdata', x(i)+[0 0], 'Ydata',[z0 z1]*dz);	% remove zero line	line( 'Color',linecolor,'EraseMode','background',  ...	 'LineWidth',linewidth, ...	 'Xdata', tr+x(i), 'Ydata',z);	% negatives line   else % zeros trace	line( 'Color',linecolor,'EraseMode','background',  ...	 'LineWidth',linewidth, ...         'Xdata', [x(i) x(i)], 'Ydata',[zstart zend]);   end;end;