Finding of arg max of a function using Gradient descent

2 次查看（过去 30 天）
Murali Krishna AG
编辑： Murali Krishna AG 2022-7-8
Let F=abs(a+bx)^2
Problem: Find x to get the maximum of F.
How to proceed with graident descent to solve this problem in matlab?
  2 个评论
John D'Errico
John D'Errico 2022-7-8
PLEASE STOP posting obvious homework assignments withg no effort made.
Murali Krishna AG
Murali Krishna AG 2022-7-8
This is not home work assignment. It's a part of my research work. I am posting after many attempts.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Sam Chak
Sam Chak 2022-7-8
Ran in:
Hi @Murali Krishna AG
I usually plot the graph if possible before attempting to solve a particular problem.
In your case, I'm unsure if you want to find the maximum or minimum of .
a = 1;
b = 1;
F = @(x) abs(a + b*x).^2;
x = linspace(-4, 2);
plot(x, F(x)), grid on, xlabel('x'), ylabel('F(x)')
  7 个评论
显示 5更早的评论
Sam Chak
Sam Chak 2022-7-8
编辑：Sam Chak 2022-7-8
Ran in:
@Murali Krishna AG, I'm actually no good at gradient descent method. But @John D'Errico is a mathematician and he is very good at solving optimization problems. Anyhow, I was trying to show you that no matter what values a and b are, the function is a parabola that opens upwards. That's why I plotted it out in the first place for you to realize it by yourself.
Usually, if the question not a homework, we don't put it like "Let this equation be ... something. Find/Solve ... using this method."
Instead, we put it like, "I'm solving this problem (show equation) with this MATLAB code:
% Type MATLAB code here:
fplot('abs(a + b*x).^2')
Error using fplot
Input must be a function or functions of a single variable.
and the Error message is shown above."
Murali Krishna AG
Murali Krishna AG 2022-7-8
编辑：Murali Krishna AG 2022-7-8
@Sam Chak Okay. Thank you very much. I will change my way of posting the questions.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Get Started with MATLAB 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by