I don’t have your code or figure, so this is the best I can do:
x = linspace(0,10*pi,1000);
y = sin(2*pi*sin(x));
figure(1)
plot(x,y)
grid
axis tight
ymin = min(ylim);
yrng = diff(ylim);
xt = get(gca, 'XTick');
set(gca, 'XTickLabel', []);
nrxt = size(xt,2);
latvct = linspace(71.59, 24.06, nrxt);
lat_txt = cellstr(strsplit(num2str(latvct,'%.2f '),' '));
text([(xt(1)-xt(2))*0.5 xt], ones(1,nrxt+1)*ymin-0.05*yrng, ['Lat ' lat_txt],'HorizontalAlignment','center')
lngvct = linspace(100.71, 75.54, nrxt);
lng_txt = cellstr(strsplit(num2str(lngvct,'%.2f '),' '));
text([(xt(1)-xt(2))*0.5 xt], ones(1,nrxt+1)*ymin-0.1*yrng, ['Lon' lng_txt],'HorizontalAlignment','center')
Everything you likely need is here, but you will obviously have to experiment with it to get the result you want in your application.
It produces:
