MATLAB: Finding the Meshgrid provided a surface.

meshgrid

Hi All, given a surface, is there anyway to find the underlying meshgrid of the surface. For example, I have a surface given by function Z that has been created in the following manner:

x = -4:0.4:4; y = -8:0.4:8; [X,Y] = meshgrid(x,y);
Z = comp_z(X,Y);
    %Given just the surface, Z , is there a way to find the meshgrid that created it?

Best Answer

How are you given the surface? As a fig file? You could extract the X and Y indices of the surface:

x = -4:0.4:4; 
y = -8:0.4:8; 
[X,Y] = meshgrid(x,y);
Z = (X.*Y);
surf(X,Y,Z)
h = findobj('Type','Surface');
surfX = h.XData;
surfY = h.YData;
all(all(surfX==X))
ans = 
   1
all(all(surfY==Y))
ans = 
   1

Related Solutions

MATLAB: How plot a correct interpolation with surf plot

It happens because of different scales of data. Don't know why MATLAB get confused about it (even linear interpolation)

scale and center your data before interpolation

sc = (max(z)-min(z))/(max(y)-min(y));
y = y - mean(y);
x = x - mean(x);
y = y*sc;
x = x*sc;
yv = linspace(min(y), max(y), 50); 
zv = linspace(min(z), max(z), 50);
[Y,Z] = meshgrid(yv, zv);
X = griddata(y,z,x,Y,Z,'cubic'); 
C = griddata(y,z,c,Y,Z,'cubic');

MATLAB: How to plot only certain values in a surface plot

Two options:

1. Set Z > 4 to NaN:

[X,Y] = meshgrid(-5:.2:5);                                
Z = -0.15*sin(X).*(X) + 0.2*(Y.^2) +3 ;
Z(Z>4) = NaN;
figure
surf(X,Y,Z)

2. Use a zlim cutoff:

[X,Y] = meshgrid(-5:.2:5);                                
Z = -0.15*sin(X).*(X) + 0.2*(Y.^2) +3 ;
figure
surf(X,Y,Z)
zlim([min(zlim) 4])

There may also be other possibiloities.

Best Answer

Related Solutions

MATLAB: How plot a correct interpolation with surf plot

MATLAB: How to plot only certain values in a surface plot

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