# could anyone help me how to select four maximum values of each row in a matrix size(10,8)

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jaah navi on 29 May 2019
Commented: Walter Roberson on 29 May 2019
I am having a matrix of size(10,8) (% 10 rows and 8 columns)
I want to select 4 maximum values from each row by having the result of matrix size(4,8)(%4 rows and 8 columns)
Walter Roberson on 29 May 2019
This question does not describe what to do in the case of ties.

KALYAN ACHARJYA on 29 May 2019
Edited: KALYAN ACHARJYA on 29 May 2019
You can do it in multiple ways, let’s consider, the mat1 is matrix having size 10x8
sort_mat=sort(mat1);
result=sort_mat(7:end,:);
Another way as per @madhan ravi comment
sort_mat=sort(mat1,'descend');
result=sort_mat(1:4,:)
See example
>> mat1=rand(10,8)
mat1 =
0.2599 0.5499 0.1839 0.3692 0.5752 0.6477 0.7802 0.8176
0.8001 0.1450 0.2400 0.1112 0.0598 0.4509 0.0811 0.7948
0.4314 0.8530 0.4173 0.7803 0.2348 0.5470 0.9294 0.6443
0.9106 0.6221 0.0497 0.3897 0.3532 0.2963 0.7757 0.3786
0.1818 0.3510 0.9027 0.2417 0.8212 0.7447 0.4868 0.8116
0.2638 0.5132 0.9448 0.4039 0.0154 0.1890 0.4359 0.5328
0.1455 0.4018 0.4909 0.0965 0.0430 0.6868 0.4468 0.3507
0.1361 0.0760 0.4893 0.1320 0.1690 0.1835 0.3063 0.9390
0.8693 0.2399 0.3377 0.9421 0.6491 0.3685 0.5085 0.8759
0.5797 0.1233 0.9001 0.9561 0.7317 0.6256 0.5108 0.5502
>> sort_mat=sort(mat1)
sort_mat =
0.1361 0.0760 0.0497 0.0965 0.0154 0.1835 0.0811 0.3507
0.1455 0.1233 0.1839 0.1112 0.0430 0.1890 0.3063 0.3786
0.1818 0.1450 0.2400 0.1320 0.0598 0.2963 0.4359 0.5328
0.2599 0.2399 0.3377 0.2417 0.1690 0.3685 0.4468 0.5502
0.2638 0.3510 0.4173 0.3692 0.2348 0.4509 0.4868 0.6443
0.4314 0.4018 0.4893 0.3897 0.3532 0.5470 0.5085 0.7948
0.5797 0.5132 0.4909 0.4039 0.5752 0.6256 0.5108 0.8116
0.8001 0.5499 0.9001 0.7803 0.6491 0.6477 0.7757 0.8176
0.8693 0.6221 0.9027 0.9421 0.7317 0.6868 0.7802 0.8759
0.9106 0.8530 0.9448 0.9561 0.8212 0.7447 0.9294 0.9390
>> resul1=sort_mat(7:10,:)
resul1 =
0.5797 0.5132 0.4909 0.4039 0.5752 0.6256 0.5108 0.8116
0.8001 0.5499 0.9001 0.7803 0.6491 0.6477 0.7757 0.8176
0.8693 0.6221 0.9027 0.9421 0.7317 0.6868 0.7802 0.8759
0.9106 0.8530 0.9448 0.9561 0.8212 0.7447 0.9294 0.9390
>>
jaah navi on 29 May 2019
thanks.

Guillaume on 29 May 2019
Edited: Guillaume on 29 May 2019
As I commented here (please don't ask the same question multiple times, thus wasting people's time), the simplest way in modern matlab (R2017b or later) is with maxk:
result = maxk(yourmatrix, 4)