How to Generate a Given Shaped Cluster of Data Points?
9 views (last 30 days)
Show older comments
Hi,
I am trying to generate some example graphs of data with irregular distribution shapes. I want a simple scatter plot of a data cluster that looks like a "C", a cluster that looks kind of like a squished jellybean, and a cluster that has tightly clustered points on the left-hand tail and disperse points on the right hand. Is there like a drawing tool where Matlab would randomly fill the space that I pre-selected? Is there a good way to randomly make these data clusters, or do I just need to define them by hand?
Thanks, Cyndi
1 Comment
Answers (1)
KSSV
on 16 Aug 2018
I would download the required shape image from google....get the boundary of the shape and generate random points inside the shape. Check the below example.
I = imread('Letter_c.svg.png') ;
I = rgb2gray(I) ;
[y,x] = find(~I) ;
idx = boundary(x,y) ;
x = x(idx) ; y = y(idx) ;
% Generate random numbers
ax = min(x) ; bx = max(x) ;
ay = min(y) ; by = max(y) ;
N = 10000 ;
xx = (bx-ax).*rand(N,1) + ax;
yy = (by-ay).*rand(N,1) + ay;
% Get points inside the C shape
idx = inpolygon(xx,yy,x,y) ;
figure
hold on
plot(x,y,'b')
plot(xx(idx),yy(idx),'.r')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/193724/image.png)
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/193729/image.bmp)
0 Comments
See Also
Categories
Find more on Scatter Plots in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!