function wigb (a,scal,x,z,amx)%WIGB: Plot seismic data using wiggles%必須徹底弄明白這個函數(shù)%  WIGB(a,scal,x,z,amx) %%  IN    a: seismic data%        scale: multiple data by scale%        x: x-axis;%        z: vertical axis (time or depth)%	 x and z are vectors with offset and time.%%	 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:% 	Xingong Li, Dec. 1995% Changes: %	Jun11,1997: add amx% 	May16,1997: updated for v5 - add 'zeros line' to background color% 	May17,1996: if scal ==0, plot without scaling% 	Aug6, 1996: if max(tr)==0, plot a line %   07-7-13,半懂if nargin == 0       %默認情況下10道,10采樣點     nx=10;nz=10;     a = rand(nz,nx)-0.5; end;[nz,nx]=size(a); %nz采樣點數(shù),nx道數(shù)trmx= max(abs(a));   %trmx記錄每一道的絕對值的最大值if (nargin <= 4); amx=mean(trmx);  end;%默認情況下,amx即為各道振幅絕對值最大值的平均值if (nargin <= 2); x=[1:nx]; z=[1:nz]; end;%默認情況下的x,z值if (nargin <= 1); scal =1; end;%默認情況下的縮放比例為1if nx <= 1; disp(' ERR:PlotWig: nx has to be more than 1');return;end;%道數(shù)小于等于1道,顯示錯誤信息 % take the average as dx	dx1 = abs(x(2:nx)-x(1:nx-1)); 	dx = median(dx1);%在標注x軸的情況時,根據(jù)標注大小,必須對所有數(shù)據(jù)處理一下 dz=z(2)-z(1); xmx=max(a(:)); xmn=min(a(:)); %所有數(shù)據(jù)點的最大值和最小值 if scal == 0; scal=1; end;%縮放比設定為1 a = a * dx /amx; %在沒有指定x,z的情況下,dx=1 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', ...   'XAxisLocation','top', ...  'XLim', [x1 x2], ...  'YDir','reverse', ...  'YLim',[z1 z2]);%對坐標軸進行一些設置,并設置了坐標軸上的最大與最小值,x軸上移,受math啟發(fā).學會自己查set(gca) 	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) );	% 符號不同,說明什么,有過零點啊	npos = length(i1);%零點個數(shù)	%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;