Find min and max in groups

3 次查看(过去 30 天)
I have 2 vectors of equal dimension, A and B. To each value of A corresponds a value of B, but equal values of A can correspond to different values of B.
I need to obtain a cell array, "Min", whose cells are vectors with the indexes of the minimum values of B and another cell array, "Max", with the maximum values. The position in each cell array is indicated by the value of A.
For example, if
A = [12, 11, 12, 5, 3, 10, 5]; B = [0.1, 0.1, 0.1, 0.7, 0.4, 0.3, 0.2]
Then:
Min = {0 ,0 ,5 ,0 ,4 ,0 ,0 ,0 ,0 ,6 ,2 ,(1, 3)}; Max = {0 ,0 ,5 ,0 ,4 ,0 ,0 ,0 ,0 ,0 ,0 ,2 ,(1, 3)}
Because of:
a_1 = 12 ; b_1 = 0.1
a_3 = 12 ; b_3 = 0.1
min(0.1, 0,1) = 0.1 => C_12 = (1, 3); max(0.1, 0.1) = 0.1 => D_12 = (1, 3)
a_2 = 11 ; b_2 = 0.1
min(0.1) = 0.1 => C_11 = (2); max(0.1) = 0.1 => D_11 = 2
...
Intiutively, it seems that it could be done in batch using groups.
Would anyone know how to do it? Thanks in advance

采纳的回答

Stephen23
Stephen23 2024-5-14
编辑:Stephen23 2024-5-14
A = [12, 11, 12, 5, 3, 10, 5];
B = [0.1, 0.1, 0.1, 0.7, 0.4, 0.3, 0.2];
X = 1:numel(A);
Fmax = @(x){x(max(B(x))==B(x))};
Fmin = @(x){x(min(B(x))==B(x))};
Cmax = accumarray(A(:),X(:),[],Fmax,{0});
Cmax{:}
ans = 0
ans = 0
ans = 5
ans = 0
ans = 4
ans = 0
ans = 0
ans = 0
ans = 0
ans = 6
ans = 2
ans = 2x1
1 3
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
Cmin = accumarray(A(:),X(:),[],Fmin,{0});
Cmin{:}
ans = 0
ans = 0
ans = 5
ans = 0
ans = 7
ans = 0
ans = 0
ans = 0
ans = 0
ans = 6
ans = 2
ans = 2x1
1 3
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
  1 个评论
Sergio Rojas Blanco
Thank you very much. it works perfectly and elegantly!
You answer everything :D

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 Graphics Object Programming 的更多信息

标签

产品


版本

R2024a

Community Treasure Hunt

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

Start Hunting!

Translated by