MATLAB: Regular meshgrids in MATLAB

matlab codermeshgrid

Hi I have created the mesh grid by using

[X,Y]=meshgrid(lon,lat);% code

I want to superimpose the mesh onto the digital elevation model to extract the geographical coordinates of the nodes.

Best Answer

YOu DEM should be having a grid and the respective H values. Use 2D interpolation i.e interp2 to get DEM values at your grid.

Check the below demo code:

[X,Y,Z] = peaks(100) ;   % your DEM say
x0 = -2 ; x1 = 2 ;   % Want to extract top these limits 
y0 = -1 ; y1 = 0 ;
N = 100 ;
x = linspace(x0,x1,N) ;
y = linspace(y0,y1,N) ;
[Xi,Yi] = meshgrid(x,y) ;
Zi = interp2(X,Y,Z,Xi,Yi) ;
subplot(121)
pcolor(X,Y,Z) ; shading interp 
subplot(122)
pcolor(Xi,Yi,Zi) ; shading interp ;

Related Solutions

MATLAB: Convert X,Y,Z column data into equally spacing grid of X,Y and corresponding Z

Let X,Y,Z be your data.

N = 500 ;
xi = lisnpace(min(X),max(X),N) ;
yi = lisnpace(min(Y),max(Y),N) ;
[Xi,Yi] = meshgrid(xi,yi) ;
Zi = griddata(X,Y,Z,Xi,Yi) ;

MATLAB: Create an interpolated grid

% new interpolated grid 

lonx=min_x:20:max_x;
laty=min_y:20:max_y;
[Xi,Yi]=meshgrid(lonx,laty);
bathymetry=interp2(XX,YY,ZZ,Xi,Yi);
%surf(XX,YY,ZZ);

%ZZ(ZZ>0)=nan; 

figure(1)
%pcolor(XX,YY,ZZ),shading interp ,colorbar;

pcolor(Xi,Yi,bathymetry),shading flat ,colorbar;  % if error transpose bathymetry and see
saveas(gcf,'bat_fine','eps');

Also you can striaght away try this:

clear;
format long e
%open file  xyz 
T=readtable('points.txt');
A=T{:,:};
X=A(:,1);
Y=A(:,2);
Z=A(:,3);
min_x=min(X);
max_x=max(X);
min_y=min(Y);
max_y=max(Y);
n=length(X);
% new interpolated grid 
lonx=min_x:20:max_x;
laty=min_y:20:max_y;
[Xi,Yi]=meshgrid(lonx,laty);
bathymetry=interp2(X,Y,Z,Xi,Yi);
ZZ = griddata(X,Y,Z,Xi,Yi);
%surf(XX,YY,ZZ);
%ZZ(ZZ>0)=nan; 
figure(1)
%pcolor(XX,YY,ZZ),shading interp ,colorbar;
pcolor(lonx,laty,bathymetry),shading flat ,colorbar;  % if error transpose the bathymetry 
saveas(gcf,'bat_fine','eps');

Best Answer

Related Solutions

MATLAB: Convert X,Y,Z column data into equally spacing grid of X,Y and corresponding Z

MATLAB: Create an interpolated grid

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