creating an image by (x,y) coordinates and value (no grid)

Hey,

I have a nX3 matrix where the first two colunms are x and y coordinates of the sample point and the third is the value in that point.

I want to creat an image (or a plot) showing the values in the coresponding coordinates without using a grid.

Is it possible?

Answer 1

[Ameer Hamza]

see griddata(): https://www.mathworks.com/help/matlab/ref/griddata.html or scatteredInterpolant(): https://www.mathworks.com/help/matlab/ref/scatteredinterpolant.html. For example

M = rand(1000, 3);
x = M(:,1);
y = M(:,2);
V = M(:,3);

xg = linspace(min(x), max(x), 100);
yg = linspace(min(y), max(y), 100);
[Xg, Yg] = meshgrid(xg, yg);
Vg = griddata(x, y, V, Xg, Yg);

[Oded Scharf]

Thank you, but I don't want to creat a 3D plot. I want to creat an image, like a heat map.

is there a way to do that?

[Ameer Hamza]

It does not create a 3D plot. It creates a 2D matrix (Vg), which can be considered an image. At the end of my code, you can write use pcolor

pcolor(Vg)

[Oded Scharf]

Thanks!