psliceuv

 PSLICEUV plots a horizontal matrix of 
          velocity from ECOMSI using arrows

  USAGE: h=psliceuv(x,y,w,isub,sca,color)
 x is array of x points
 y is array of y points 
 w is array of velocities
 isub is number to subsample
 sca is scale factor for arrows
 color is color for arrows
 
 EXAMPLE:  psliceuv(x,y,w,3,20,'white');

0001 function h=psliceuv(x,y,w,isub,sca,color)
0002 %
0003 % PSLICEUV plots a horizontal matrix of
0004 %          velocity from ECOMSI using arrows
0005 %
0006 %  USAGE: h=psliceuv(x,y,w,isub,sca,color)
0007 % x is array of x points
0008 % y is array of y points
0009 % w is array of velocities
0010 % isub is number to subsample
0011 % sca is scale factor for arrows
0012 % color is color for arrows
0013 %
0014 % EXAMPLE:  psliceuv(x,y,w,3,20,'white');
0015 %
0016 if(~exist('isub')),
0017   isub=2;
0018 end
0019 if(~exist('sca')),
0020   sca=1e4;
0021 end
0022 if(~exist('color')),
0023   color='white';
0024 end
0025 [m,n]=size(w);
0026 w=w([isub:isub:m],[isub:isub:n]);
0027 x=x([isub:isub:m],[isub:isub:n]);
0028 y=y([isub:isub:m],[isub:isub:n]);
0029 ig=find(finite(w));
0030 h=arrows(x(ig),y(ig),w(ig),sca,color);