查找每个值的最后一次出现的索引

问题描述

我有一个像这样的向量:

I have a vector like this :

>> v = [1 1 1 2 2 3 4 4 4 4 4 5 5]'

v =

     1
     1
     1
     2
     2
     3
     4
     4
     4
     4
     4
     5
     5

对向量进行排序.每个值可以有任意数量.我需要找到每个值最后一次出现的索引.在这种情况下，它将返回以下内容:

The vector is sorted. There can be any number of each values. I need to find the index of the last occurence of each value. In this case, it would return this :

answer =

     3    % index of the last occurence of "1"
     5    % index of the last occurence of "2"
     6    % index of the last occurence of "3"
    11    % index of the last occurence of "4"
    13    % index of the last occurence of "5"

推荐答案

感谢@trumpetlicks，答案是 unique .

Thanks to @trumpetlicks, the answer is unique.

>> v = [1 1 1 2 2 3 4 4 4 4 4 5 5 6]'

v =

     1
     1
     1
     2
     2
     3
     4
     4
     4
     4
     4
     5
     5
     6

>> [~, answer] = unique(v)

answer =

     3
     5
     6
    11
    13
    14

在最新版本的MCR(R2013?)中， unique 的行为已更改.要获得相同的结果，必须使用 unique(v，'legacy');

In more recente version of the MCR (R2013 ?), the behavior of unique has changed. To get the same result, you must use unique(v, 'legacy');

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