How to interplote and meshgrid 2D scatter plot (bounded by an ir-regular surface)?

Hi everyone,

I require interpolating a 2d scatter plot and then creating a mesh grid to find the average value within each grid cell along with the cell's central location.

Here is what i did so far:

Step 1: Plotting irregular surface

data=readmatrix('area.csv');
x=data(:,1);
y=data(:,2);
z=data(:,3);
plot(x, y, 'blue')
hold on 

Step 2: Scatter plot

dat=readmatrix('combine.csv');
x1=dat(:,2);
y1=dat(:,3);
c1=dat(:,4);
plot(x1, y1, 'blue')
scatter(x1,y1,[],c1,'filled')
colorbar
colormap jet
hold off

To do ?

I require to plot these scatter pl;ot by interploation to get a higher resolution, like as below:

Additionally, I need to creat a mesh grid with teh bounded area and need to calcualte the depth value within each grid point along with the central location of grid.

Thank you!

(Data is attached).

Answer 1

[Mathieu NOE]

hello

this should help you move forward

side by side the original plot and once resampled (grid data)

% Step 1: Plotting irregular surface 
data=readmatrix('area.csv');
x=data(:,1);
y=data(:,2);
z=data(:,3);
plot(x, y, 'blue')
hold on 

% Step 2: Scatter plot
dat=readmatrix('combine.csv');
x1=dat(:,2);
y1=dat(:,3);
c1=dat(:,4);
% plot(x1, y1, 'blue')
subplot(1,2,1),
scatter(x1,y1,[],c1,'filled')
title('original data')
colorbar
colormap jet
hold off

% create a mesh , and find points that are inside the border defined by x &
% y 
N = 200;
[X,Y] = meshgrid(linspace(min(x),max(x),N),linspace(min(y),max(y),N));
in = inpolygon(X(:),Y(:),x,y);
xin = X(in);
yin = Y(in);
clear X Y
vq = griddata(x1,y1,c1,xin,yin);
subplot(1,2,2),
scatter(xin, yin, [], vq, 'filled') 
title('resampled data')

colorbar
colormap jet

hold off