function[data,h,hc]=provec(varargin)%PROVEC  Generate progressive vector diagrams (simple and fancy).%%   Simple provecs:%%     PROVEC(U,V,DELTAT) generates a simple progressive vector diagram%     plotting cumsum(U*DELTAT) vs cumsum(V*DELTAT).  U and V are%     column vectors, or matrices with time oriented in columns.%     DELTAT (optional) must be in units of seconds and defaults to%     one hour (3600 s).  U and V must have units of cm/s.%  %     PROVEC(CV,DELTAT), where CV=U+iV, also works.%%     INT=PROVEC(...) outputs the integrated dispacement INT in km.%	 %   Fancy provecs:%%     A fancy provec use SCATTER to plot change the color and/or sizes%     of the points according to another parameter, say density.  A%     colorbar is also plotted.%%     PROVEC(U,V,C,DELTAT) uses C as the symbol color.  The array C%     must have the same size as U and V.%%     PROVEC(U,V,C,S,DELTAT) also uses S as the symbol size.  The%     array S must have the same size as U and V.%	%     PROVEC(CV,C,DELTAT) and PROVEC(CV,C,S,DELTAT) also work.%%     Note that since SCATTER is slow for large datasets, it is useful%     to decimate the data before plotting.  This is accomplished%     using PROVEC(...,INDEX,[DELTAT]), where INDEX is placed just%     before the optional DELTAT.  Then only the points INT(INDEX,:)%     of the integrated trajectory are plotted.%%     [INT,H,HC]=PROVEC returns the intergrated displacement INT, the%     handle H to the data, and the handle HC to the colorbar axis.%%   PROVEC(DCOL,...), where DCOL is a scalar or a row vector,%   specifies that the columns of the data are to by offset by amount%   DCOL after plotting, for both simple and fancy provecs.  %%   If DCOL is a scalar, then successive columns after the first are%   offset by amount -DCOL.  If DCOL is a row vector, then it%   specifies the offset for each column of the data.%%   As an example,%  %          load bravo94,use bravo.rcm,use bravo.cat%          th=100*detrend(th(:,3));%          [int,h,hc]=provec(cv(:,3),th,20+0*th,[1:10:4000]);%          caxis([-8 8])%%   makes part of Figure 6b of Lilly and Rhines (2002) JPO.%         %   Usage: int=provec(cv);%          [int,h,hc]=provec(cv,c,index);%          [int,h,hc]=provec(cv,c,s,index);%          [int,h,hc]=provec(cv,c,s,index,deltat);%          [int,h,hc]=provec(dcol,cv,c,s,index,deltat);%   _________________________________________________________________%   This is part of JLAB --- type 'help jlab' for more information%   (C) 1999--2006 J.M. Lilly --- type 'help jlab_license' for details        inunits=100;outunits=1000;factor=100*1000;bcolor=0;defsize=5;na=nargin;deltat=3600;%/********************************************************%Look for initial row vectoroffs=0;if isrow(varargin{1}) || isscalar(varargin{1});  offs=varargin{1};  na=na-1;  varargin=varargin(2:end);end%\********************************************************if length(varargin{end})==1  deltat=varargin{end};  na=na-1;endindex=[];if length(varargin{na})~=length(varargin{1})  index=varargin{na};  na=na-1;endc=[];if isreal(varargin{1})  data=varargin{1}+sqrt(-1)*varargin{2};  if na>2      c=varargin{3};  end  if na>3      s=varargin{4};  else      s=defsize+zeros(size(data));  end else  data=varargin{1};  if na>1      c=varargin{2};  end  if na>2      s=varargin{3};  else      s=defsize+zeros(size(data));  end enddata=vswap(data,nan,0);data=cumsum(data)*deltat/factor;if ~offs==0  if isscalar(offs)    offs=-[0:1:size(data,2)-1]*offs;  end  if length(offs)~=size(data,2)    error('Length of DCOL must equal number of columns of the data.')  end  for i=1:size(data,2)      data(:,i)=data(:,i)+offs(i);  endendif ~isempty(index);  data=data(index,:);  if ~isempty(c);    c=c(index,:);  end  if ~isempty(s);    s=s(index,:);  endendif isempty(c)	h=plot(data);else 	bcolor=1;        vcolon(data,s,c);	if any(isnan(s))	  error('S cannot contain NANs.')	end	if any(isnan(c))	  error('C cannot contain NANs.')	end	h=scatter(real(data),imag(data),s,c,'filled');endxlabel('Displacement eastward (km)')ylabel('Displacement northward (km)')set(gca,'box','on')set(gca,'dataaspectratio',[1 1 1])pos=get(gca,'position');%put a colorbar if neededif bcolor	ax=gca;	hc=colorbar;	posc=get(hc,'position');	set(hc,'position',[posc(1) pos(2) posc(3) pos(4)])	%the above doesn't take care of the relative size	%problem--- instead, try to change aspect ratio	axes(ax)endhold onif nargout ==0    clear data h hcend