Calculate the Gradient of a given function using the forward and central quotients.

1 次查看（过去 30 天）

kai kai 2021-1-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/715688-calculate-the-gradient-of-a-given-function-using-the-forward-and-central-quotients

评论： kai kai 2021-1-13

I am very bad at this, it would be hard for me to calculate it even for only one variable, but now that I have to calculate the Gradient i am completely lost.

Please help me out, any sort of help is very much appreciated.

My failed code:

function f1x = vordiff(f,x,h,y,z)
%Vorwärtsdifferenzenquotienten
  function f = f(x,y,z)
    f = (4*x+3*y+2*z)*e^(-3*x^2)-4*y^2-8*x*y-2*z^2
  end
f1x = (f(x+h)-f(x))/h;
f1z = (f(z+h)-f(z))/h;
f1y = (f(y+h)-f(y))/h;
end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

KSSV 2021-1-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/715688-calculate-the-gradient-of-a-given-function-using-the-forward-and-central-quotients#answer_596928

function f1x = vordiff(f,x,h,y,z)
%Vorwärtsdifferenzenquotienten
syms x y z ;
f = (4*x+3*y+2*z)*e^(-3*x^2)-4*y^2-8*x*y-2*z^2
fx = diff(f,x) ; 
fy = diff(f,y) ;
fz = diff(f,z) ; 
end