Here is an example of plotting data that was created using the "meshgrid" function of the attached data. You can also find the answer in this thread.
clear
close all
%% Get experimental data
path = 'C:\';
filename = 'data.mat';
load(fullfile(path,filename));
%down sample factor
fsample = 30;
%number of x-mesh points
nx = 100;
%number of y-mesh points
ny = 100;
% time vector (s)
t = data.measure.t;
t = downsample(t,fsample);
% x-position vector (um)
x = data.measure.x;
x = downsample(x,fsample);
% y-position vector (um)
y = data.measure.y;
y = downsample(y,fsample);
%% generate z-data using experimental data points for visual example
% x-wavelength
Lx = 10;
% y-wavelength
Ly = 6;
% z-points for heat map
z = sin(2*pi/Lx*x) + cos(2*pi/Ly*y);
%% Choose mesh points
xmin = min(x);
xmax = max(x);
ymin = min(y);
ymax = max(y);
%sample points for mesh
xSample = linspace(xmin,xmax,nx);
ySample = linspace(ymin,ymax,ny);
%2D array of x and y points
[xMesh, yMesh] = meshgrid(xSample,ySample);
%interpolate z-data using mesh points
zMesh = griddata(x,y,z,xMesh,yMesh,'cubic');
%% Plot that ish
figure(1)
scatter3(x,y,z,5,z)
colormap(gca,"winter")
xlabel('x-Position (um)')
ylabel('y-Position (um)')
zlabel('Intensity (a.u.)')
title('3D Scatter Plot')
figure(2)
mesh(xMesh,yMesh,zMesh)
axis tight;
hold on
plot3(x,y,z,'.r','MarkerSize',5)
hold on
xlabel('x-Position (um)')
ylabel('y-Position (um)')
zlabel('Intensity (a.u.)')
title('Mesh + Scatter Plot')
figure(3)
h = surf(xMesh,yMesh,zMesh);
shading interp
set(h,'LineStyle','none')
xlabel('x-Position (um)')
ylabel('y-Position (um)')
zlabel('Intensity (a.u.)')
title('Surface Plot')
