Delete all repeatation number

1 次查看（过去 30 天）
eko supriyadi
eko supriyadi 2022-6-1
评论： eko supriyadi 2022-6-1
Hi matlab community,
Say i have the matrix:
a = [1 2 2 3 2 4 5 6 7 8 6]
and i want delete all repetation number there, so i want like this result:
a = [1 3 4 5 7 8]
you can see, i want remove number 2 and 6..how to solve it?
and another problem (if we work with big array).. say i have information that repeat number are 2 and 6, any suggestions for a looping construct? below looping is fail!
repeat=[2;6];
a = [1 2 2 3 2 4 5 6 7 8 6]
for i=1:length(repeat)
a(a==a(repeat(i)))=[]
end
from these looping, will result:
a =
1 3 4 5 6 8 6
you can see, that result still produce repeat number, namely 6. .tks community :)

请先登录，再回答此问题。

采纳的回答

Jan
Jan 2022-6-1
% Your code
repeat=[2;6];
a = [1 2 2 3 2 4 5 6 7 8 6]
for i=1:length(repeat)
a(a==a(repeat(i)))=[]
end
A small modification solves the promlem:
for i=1:length(repeat)
a(a == repeat(i)) = [];
% not a(repeat(i)) !
end
Or easier:
a(ismember(a, [2,6])) = []
or
a = setdiff(a, [2,6], 'stable')

更多回答（4 个）

Stephen23
Stephen23 2022-6-1
Ran in:
a = [1,2,2,3,2,4,5,6,7,8,6];
[c,x] = histc(a,unique(a));
a(c(x)>1) = []
a = 1×6
1 3 4 5 7 8
Bruno Luong
Bruno Luong 2022-6-1
Ran in:
a = [1 2 2 3 2 4 5 6 7 8 6]
a = 1×11
1 2 2 3 2 4 5 6 7 8 6
[u,~,j]=unique(a);
a(ismember(a,u(accumarray(j,1)>1)))=[]
a = 1×6
1 3 4 5 7 8
  1 个评论
Jan
Jan 2022-6-1
编辑：Jan 2022-6-1
Ran in:
Or with omitting ismember:
a = [17 2 2 3 2 4 5 6 7 8 6];
[~, ~, ic] = unique(a);
mult = (accumarray(ic, 1) <= 1);
as = a(mult(ic))
as = 1×6
17 3 4 5 7 8

请先登录，再进行评论。

KSSV
KSSV 2022-6-1
Ran in:
REad about unique.
a = [1 2 2 3 2 4 5 6 7 8 6]
a = 1×11
1 2 2 3 2 4 5 6 7 8 6
iwant = unique(a)
iwant = 1×8
1 2 3 4 5 6 7 8
Jan
Jan 2022-6-1
Ran in:
a = [1 2 2 3 2 4 5 6 7 8 6];
[S, idx] = sort(a(:).');
m = [false, diff(S) == 0];
ini = strfind(m, [false, true]);
m(ini) = true; % Mark 1st occurence in addition
T(idx) = m; % TRUE for multiple occurences
b = a(~T)
b = 1×6
1 3 4 5 7 8

类别

在 Help Center 和 File Exchange 中查找有关 Image Processing Toolbox 的更多信息

标签

产品


版本

R2021a

Community Treasure Hunt

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

Start Hunting!

Translated by