- Use boundary to get the boundary of your required region.
- Use inpolygon with the generated grid and boundary points to get the points lying inside the area of interest.
- Useing the indices generated from inpolygon, you can get your required points.
Generate (X,Y) grid coordinates from within contour boundary
16 views (last 30 days)
Show older comments
Hi Everyone
I have the (X,Y,Z) coodinates for a contourf plot.
I want to extract sample (X2,Y2) coordinates for a given size within the contour area under the input Z value threshold.
E.g. I only want Z values for Z_threshold = 10. If I input grid_size = 5, I want to get (X2,Y2) points spaced at 5m x 5m within the threshold contourf(X,Y,Z) area.
I can create the right size grid by using linspace, but I don't know how to restrict these coordinates to be only from within the desired contour area though?
load('contour_data.mat','X','Y','Z');
Z_threshold = 10;
grid_size = 20;
Z(Z > Z_threshold )= NaN;
contourf(X,Y,Z);
hold on
x_grid = linspace(min(X(:)), max(X(:)), range(X(:))/grid_size);
y_grid = linspace(min(Y(:)), max(Y(:)), range(Y(:))/grid_size);
[X2,Y2] = meshgrid(x_grid,y_grid);
plot(X2,Y2,'.r');
hold off
I only want (X2,Y2) from within the green circled zone below. Note that (X2,Y2) don't correspond to (X,Y) points.
![contourf_grid.png](https://www.mathworks.com/matlabcentral/answers/uploaded_files/261078/contourf_grid.png)
Thanks for any advice :)
0 Comments
Accepted Answer
KSSV
on 10 Jan 2020
Refer this link: https://in.mathworks.com/matlabcentral/answers/499017-interpolation-with-non-zero-data-only-when-using-griddata for the same question.
More Answers (0)
See Also
Categories
Find more on Contour Plots in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!