function plotSQ(SQ,j,k)
% plotSQ plot TS diagram from Climatology 
%
% First, load the SQ structure as:
%           >> load('climSQ.mat'); 
% B), Call as:
%           >> plotSQ(SQ,j,k)
%


tmin=2;tmax=30;
smin=34;smax=37;
rmin=1020;rmax=1030;
nr=11;
n=25;
[tgrid,sgrid]=meshgrid(linspace(tmin,tmax,n),linspace(smin,smax,n));
rho=sw_dens0(sgrid,tgrid); 

[c,h]=contour(sgrid,tgrid,rho,linspace(rmin,rmax,nr));
set(h,'EdgeColor','k')
clabel(c,h)

datasqu=[SQ(j,k).T SQ(j,k).S SQ(j,k).Z SQ(j,k).D];

idx=find(datasqu(:,4)>200);
line(datasqu(idx,2),datasqu(idx,1),'Color','r','Marker','.','LineStyle','none','MarkerSize',14);
idx=find(datasqu(:,4)<=200);
line(datasqu(idx,2),datasqu(idx,1),'Color','g','Marker','.','LineStyle','none','MarkerSize',14);

line(SQ(j,k).Savg,SQ(j,k).Tavg,'Color','k')

axis([34 37 2 30]);
xlabel('S')
ylabel('T')
title(['TS from square ' int2str(j) ',' int2str(k)],'FontSize',17)

grid