How to extract area using inpolygon

Hello everyone,

I need to do analysis on just rectangular part of my figure. Therefore, I tried to extract that area using inpolygon. My data is lat = 406x270 and lon = 406x270. I have plotted temperature which is 2030x1354.

Using the code below:

xv= [104.61, 102.98, 109.37, 109.52];
yv = [19.93, 25.03,  25.01, 19.98];
in = inpolygon(lon,lat,xv,yv); 
figure
plot(xv,yv) % polygon
axis equal
hold on 
plot(lon(in),lat(in),'r+') % points inside
plot(lon(~in),lat(~in),'bo') % points outside
hold off

I just can't figure out what is wrong in my code. Kindly tell me what's wrong here? Thank you.

Answer 1

[KSSV]

Check your polygon coordinates. They are not up to the mark as shown in the first figure.

xv= [104.61, 102.98, 109.37, 109.52];
yv = [19.93, 25.03,  25.01, 19.98];
patch(xv,yv,'r')

[IMC]

Thank you for your reply.

But I have one question here about this statement 'Check your polygon coordinates' . Does this mean I have not selected the coordinates correctly?

[KSSV]

Yes.