Multivariate Gaussian user defined function

1 次查看(过去 30 天)
Hi
I want to create a hard coded multivariate gaussian function. I know there is an already existing matab function but I need to create another function for my project.
The Multivariate Gaussian Distribution equation given is as follows:
The function has to give a final plot of the gaussian bump using the imagesc in 2D.
%% Some code that I have already tried
function [z] = mygaussian2Dplot(X,mu,sigma)
e = 2.17;
L = X(1);
Y = X(2);
sigma_l = sigma(1).*L;
sigma_y = sigma(2).*Y;
z = 1/2.*sigma_l.*sigma_y.*pi*e.*(-L.^2/2.*sigma_l.^2 - Y.^2/2.*sigma_y.^2);
figure
imagesc(z)
title('Multivariate Gaussian Distribution')
xlabel('x')
ylabel('f(x)')
end
  1 个评论
the cyclist
the cyclist 2019-11-8
Note that e is closer to 2.71, not 2.17.
You could also have used exp(1) there, for an even closer approximation.
Your code simply multiplied by e in your expression, rather than raising e to the desired power in the gaussian formula. That is another thing I fixed in my solution.

请先登录,再进行评论。

采纳的回答

the cyclist
the cyclist 2019-11-8
编辑:the cyclist 2019-11-8
I made a few changes:
  • Define L as the first column of X, not just first value
  • Ditto Y for second column
  • Changed a couple matrix operations to elementwise operations, in the definition of z
L = X(:,1);
Y = X(:,2);
sigma_l = sigma(1).*L;
sigma_y = sigma(2).*Y;
z = 1/2.*sigma_l.*sigma_y.*pi.*exp(-L.^2./2.*sigma_l.^2 - Y.^2./2.*sigma_y.^2);
figure
imagesc(z)
title('Multivariate Gaussian Distribution')
xlabel('x')
ylabel('f(x)')
  3 个评论
the cyclist
the cyclist 2019-11-8
L = X(:,1);
Y = X(:,2);
sigma_l = sigma(1).*L;
sigma_y = sigma(2).*Y;
[LL,YY] = ndgrid(L,Y);
z = 1/2.*sigma_l.*sigma_y.*pi.*exp(-LL.^2./2.*sigma_l.^2 - YY.^2./2.*sigma_y.^2);
BBB
BBB 2019-11-8
Hi
Thank you so much! It works well :)
Really appreciate it!

请先登录,再进行评论。

更多回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Mathematics 的更多信息

Community Treasure Hunt

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

Start Hunting!

Translated by