fid=fopen('tpg_ref.av11-341f2','r');

junk = fread(fid,1,'long');
iz = fread(fid,1,'long')
jz = fread(fid,1,'long')
ylat = fread(fid,2,'float32')
xlon = fread(fid,2,'float32')
junk = fread(fid,2,'long');
izjz = iz*jz;

ssh = fread(fid,izjz,'float32'); ssh = reshape(ssh,iz,jz); ssh = ssh';
ssh(33,:)

missing=-9999.;
[xx,yy]=find(ssh==missing);
nn=length(xx);
for ii=1:nn
  ssh(xx(ii),yy(ii))=NaN;
end
ssh(:,181)=ssh(:,1); xlon(2)=xlon(2)+2;
yl=ylat(1):2:ylat(2); xl=xlon(1):2:xlon(2);
scon=-160:20:180; contour(xl,yl,ssh,scon)