How to extract matrix from a bigger matrix based on threshold of each column?

조회 수: 2(최근 30일)
I have a nX3 matrix. I need to extract a matrix such that all rows crossing the threshold of each column are selected. Threshold can be assumed to be 100(column 1),200(column2) and 300(column 3 )? Please help...
  댓글 수: 1
Adam Danz
Adam Danz 2019년 12월 2일
Small examples of inputs and expected outputs are usually worth 1000 words.

댓글을 달려면 로그인하십시오.

채택된 답변

Philippe Lebel
Philippe Lebel 2019년 12월 2일
편집: Philippe Lebel 2019년 12월 2일
here is my try based on what i understood.
given a matrix a nx3:
a = [5,6,8;1,2,3;2,3,4;3,4,5;4,5,6]
a =
5 6 8
1 2 3
2 3 4
3 4 5
4 5 6
% the threshold on column 1 is 2
a_1 = a(a(:,1)>2,:)
a_1 =
5 6 8
3 4 5
4 5 6
% the treshold on column 2 is 4
a_2 = a_1(a_1(:,2)>4,:)
a_2 =
5 6 8
4 5 6
%the treshold on column 3 is 6
a_3 = a_2(a_2(:,3)>6,:)
a_3 =
5 6 8
a_3 is the matrix containing the row(s) that satisfy all tresholds.
A one-liner can be made for this operation:
a_tresh = a((a(:,1)>2)&(a(:,2)>4)&(a(:,3)>6),:)
a_tresh =
5 6 8
  댓글 수: 4
Adam Danz
Adam Danz 2019년 12월 2일
편집: Adam Danz 2019년 12월 2일
Nice job interpreting the question. I wouldn't have guessed. Too many times I guessed on other questions, spent time writing out the solution, and then found that my interpretation wasn't correct.

댓글을 달려면 로그인하십시오.

추가 답변(0개)

Community Treasure Hunt

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

Start Hunting!

Translated by