Find the maximum value and its position of a 10x10x10 matrix which meets a set of parameters.

1 次查看（过去 30 天）
Jack Holland
Jack Holland 2018-3-28
评论： Guillaume 2018-3-29
I have a 10x10x10 matrix, M, which I found by taking 3 1x10 matrices, a b and c, and turning them into a 10x10x10 matrix, A, and then multiplied A by an unknown constant. I need to find the maximum value of M and its position while it's corresponding values of a, b and c are smaller than a set of parameters.
  4 个评论
显示 2更早的评论
Jack Holland
Jack Holland 2018-3-29
I'm trying to find the biggest possible value which meets the requirement, so if the max doesn't fit then find the second biggest and if that doesn't fit then the third etc

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Guillaume
Guillaume 2018-3-29
编辑：Guillaume 2018-3-29
h = 70;
c = linspace(30,60,10);
b = linspace(1,h-2,10);
a = linspace(1,14,10);
[A, B, C]=meshgrid(a,b,c);
M = D *(C.*h-2*B.*A);
%Q = ...
%Fy = ...
isinrange= Q > Fy./(1/12*(C*h^3 - 2*A.B.^3));
[maxM, idx] = max(M(isinrange));
aAtMax = A(idx);
bAtMax = B(idx);
cAtMax = C(idx);
  3 个评论
显示 1更早的评论
Stephen23
Stephen23 2018-3-29
Guillaume defined the variable isinrange, whereas the error message shows that you apparently tried to use a non-existent name, isinrage (the mind boggles at what that variable would measure!)
Guillaume
Guillaume 2018-3-29
Saying that, the expression was missing a closing bracket (as does the original expression given in the original question). Now fixed.

请先登录，再进行评论。

更多回答（1 个）

Veera Kanmani
Veera Kanmani 2018-3-29
max_value_position=max(M);
max_value=M(max(M));
  4 个评论
显示 2更早的评论
Stephen23
Stephen23 2018-3-29
编辑：Stephen23 2018-3-29
Given that M is a 10x10x10 array, max(M) will return a 1x10x10 array. Using that as the input to find will return as many indices as there are non-zero maximum values. If all of the values are non-zero then it will simply be a list of all linear indices of that 1x10x10 array. Lets try it with a smaller example:
>> M = rand(3,3,3);
>> find(max(M))
ans =
1
2
3
4
5
6
7
8
9
How does this list of all indices of non-zero values in the output of max help to solve the problem? How are we supposed to use these indices to "Find the maximum value and its position...", as the original question requests?

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Logical 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