min MAX of several variables

Question

francesco 2013-12-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/108511-min-max-of-several-variables

编辑： dpb 2013-12-4

采纳的回答： dpb

is it possible to calculate in only one function, the min or MAX value for several variables? as for:

zal1, zal2, zal3, agg1, zgg2, zgg3 (are matrices nxn)

%

the bruteforce solution:

%

max(zal1,zal2);

max(ans,zal3);

max(ans,zgg1);

max(ans,zgg2);

maxz=max(max(max(ans,zgg3)))

%

min(zal1,zal2);

min(ans,zal3);

min(ans,zgg1);

min(ans,zgg2);

minz=min(min(min(ans,zgg3)))

is there any lean solution?

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。

Answer 1

dpb 2013-12-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/108511-min-max-of-several-variables#answer_117168

编辑：dpb 2013-12-4

在 MATLAB Online 中打开

If same size,

tmp=[zal1, zal2, zal3, agg1, zgg2, zgg3 ];
maxz=max(tmp(:));
minz=min(tmp(:));

Unfortunate can't use the (:) after the concatenation to avoid the temporary although since there are two operations it saves building twice as I doubt that the optimizer would figure out the optimization on its own.

ADDENDUM:

The whole problem illustrates why would be better, perhaps to rearrange the data structure to use cell arrays or named structures or higher dimension arrays instead of generating a series of sequentially-named variables. Then could eliminate the need to manipulate the separate variables explicitly.

ADDENDUM 2:

tmp=[zal1(:) zal2(:) zal3(:) agg1(:) zgg2(:) zgg3(:)];

gets the vector at the first go which may make a tiny speedup compared to above.