Problem longitude and latitude contour in a surface plot

Hi all,

I try to overlay the contour of the coastline of the Strait of Gibraltar into my surface plot of my datas. The bathymetry that I use is from ETOPO, and it´s the one that the has been used for the hidrodynamic model that I use. I reshape the matriz with imresize so both datas has the same dimension and the I plot it.

My problem is when I plot the supossed contour of the coast because it does't match with the end of my data.

Do you know if there is a solution for this??

Thank you in advance.

[darova]

Please explain more. It's not clear what is wrong. What is wrong? Can you show? How the result should look like?

[Miguel andres]

Yes, sorry:

The thick blue line sould be in the contour between the datas and the white part.I attach here a plot of how the contour should look like.

I already find where is the problem but I don't know how to solve it.

The size of the datas of the bathymetry (the values=0 are the contour) is 55x87 whre:

bat_lon= 87x1

bat_lat=55x1

bat_altitude=44x87

And the datas that I have plot are in a curvilinear grid of size 40x144.

I change the dimension of the bat_altitude with imresize as bat_final= imresize(bat_altitude, [40,144]), and with this, the coordanates has change (because of that the conour that should appear at the start of the white part, they appear in the middle of the map).

How can I change the matriz dimension of the batimetry without changing the coordenates?

Than you really much.

[darova]

The size of the datas of the bathymetry (the values=0 are the contour) is 55x87 whre:

bat_lon= 87x1

bat_lat=55x1

bat_altitude=44x87

Try to interpolate bat_lat variable

bat_lat1 = interp1(1:55,bat_lat,linspace(1,55,44));

[Miguel andres]

Thank you!

But this didn,t work, because the batimetry that holds the values is bat_altitude.

I think I should interpolate that variable with interp2 so I obtain a matrix 40x144.

I tried this but I get an error, maybe you can help with the code.

bat_altitude1=interp2(1:87,1:55,bat_altitude,linspace(1,87,40),linspace(1,55,144));

Thank you again

Answer 1

[darova]

Sure, use meshgrid

[m,n] = size(bat_latitude);
xx = linspace(1,n,40);
yy = linspace(1,m,144);
[x1,y1] = meshgrid(xx,yy);
[x,y] = meshgrid(1:n,1:m);
bat_altitude1 = interp2(x,y,bat_altitude,x1,y1);

[Miguel andres]

Thank you again,

But this didn't solve the problem. The contour appear in the same way that the first picture that I attach.

Maybe I have to plot the batymetry with his own lon, lat reference instead of the lon lat reference of the dtas of velocity?

[darova]

Can you attach the data?

[Miguel andres]

I can' attach them because altough I have compressed them, they are too big.

I'm pretty new here, do you know how can I send them to you?

[darova]

How big they are? What about google drive? Can you attach only part of it?

[Miguel andres]

Here ir the link to google drive:

https://drive.google.com/drive/folders/1EgfOX15PekDAfJXqSwAM4GRCHZnn-T0f?usp=sharing

I plot the velocity as:

figure

peak_vel_atl=pcolor(lon,lat,peak_mod_atl);colormap jet; colorbar,caxis([0 5])

peak_vel_atl,EdgeAlpha=0,caxis

shading interp

Thank you

[darova]

Whoa, 200mb, that is too much

Can't you overlay your contour using existing coordinates?

Example

[X,Y] = deal(zeros(20));
t = linspace(-1,1,20)*pi/4;     % define angle fo arc part
[x,y] = pol2cart(t,2);          % get cartesian arc coordinates
for i = 1:20
    X(:,i) = linspace(x(i),5,20);
    Y(:,i) = linspace(y(i),tan(t(i))*5,20);
end
Z = X*0;                        % Z = 0 (flat)
pcolor(X,Y,Z)
line(X(:,[1 end]),Y(:,[1 end]),'linew',2,'color','b')
line(X([1 end],:)',Y([1 end],:)','linew',2,'color','b')
axis equal