function pzsliceuv(x,y,w,isub,sca,color,erasemode)
% PZSLICEUV plots a zslice of velocity from ECOMSI using arrows
%  USAGE: pzslice(x,y,u,cax)
% x is array of x points
% y is array of y points 
% w is array of velocities
% sca is scale factor for arrows
% color is color for arrows
% erasemode = erasemode for arrows "none" for overplot
% 
% EXAMPLE:  pzsliceuv(x,y,w,3,0.0001,'white','none');
igood=find(~isnan(w));
ig=igood(1:isub:length(igood));
arrows4(x(ig),y(ig),w(ig),sca,color,erasemode);
