How to Generate a Given Shaped Cluster of Data Points?

4 次查看（过去 30 天）
Cynthia Dickerson
Cynthia Dickerson 2018-8-15
回答： KSSV 2018-8-16
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

请先登录，再回答此问题。

回答（1 个）

KSSV
KSSV 2018-8-16
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')

类别

在 Help Center 和 File Exchange 中查找有关 2-D and 3-D Plots 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by