limits of latitude - longitude

I had a netCDF file comprising of SST data . I plotted a graph using pcolor but now i have to plot same data for a shorter location, i have latitude longitude limits but dont know how to make plot for that specific lat lon limits . Pls help , I am attaching my initial plot

[Arnav Gupta]

I have to plot from (0-360E, 80S-50S)

Answer 1

[KSSV]

Read about interp2.

[Arnav Gupta]

Isn't there some other way ?? Some change in the existing code?

filename="filepath"
ncdisp(filename)
%degrees east = COADSX=longitude
%degrees north = COADSY = latitude
lat=ncread(filename,'COADSY')
long=ncread(filename,'COADSX')
sst=ncread(filename,'SST')
sst_march=sst(:,:,3:3)
sst_march=sst_march'
[longg, latg] = meshgrid(long, lat);
load coastlines
island = inpolygon(longg, latg, coastlon, coastlat);
sst_march(island)=NaN;
pcolor(longg,latg,sst_march)
hold on
plot(wrapTo360(coastlon), coastlat, 'r.', 'MarkerSize', 6);
set(gca, 'color', 'k');
shading flat
title('SST PLOT')

[KSSV]

dx = min(unique(long)) ;  % resolution along lon
dy = min(unique(lat)) ;  % resolution along lat

xi = 0:dx:360 ;
yi = 80:dy:50 ;
[Xi,Yi] = meshgrid(xi,yi) ; 
sst_marchi = interp2(longg,latg,sst_march,Xi,Yi) ; 

[Arnav Gupta]

since latitude has to be from 80S TO 50S shouldnt i put yi = -80:dy:-50 ;

in data it is given latitude is degrees north

[KSSV]

Thats fine..check the range or format of the lat, lon.

Answer 2

[Yang Liu]

% if you just want to show data in specific extent, set the axis limit as follows after ploting all data

ylim([-80 -50])

% if you want to plot data in specific extent, change your pcolor line as follows

sub = longg > -80 & longg < -50;

pcolor(longg(sub),latg(sub),sst_march(sub));