MATLAB Answers

Find closest value in array

조회 수: 4,577(최근 30일)
Chiranjibi
Chiranjibi 2014년 8월 25일
댓글: Adrian Aquino Arriaga 2021년 10월 8일 15:30
I have two vector(which are time stamps) like,
V N
1375471092848936 1375473384440853
1375473388165900 1375471277856598
1375471320476780 1375473388165900
1375473388947681 1375471322465961
1375473392527002 1375471335206288
.................. ..................
My goal is to find closest time in N with respect to V (i.e. find time in N which is nearly equal with V). My frame is W = 1e4, furthermore V should lies between N-W and N+W. So how do I get closest time through MATLAB? Any help would be appreciated.
Thanks

채택된 답변

Joe S
Joe S 2018년 9월 10일
편집: MathWorks Support Team 2018년 11월 27일
To compute the closest value in a vector “N” for each element of “V”, try the following code with example vectors “N” and “V”:
V = randi(10,[5 1])
N = randi(10,[5 1])
A = repmat(N,[1 length(V)])
[minValue,closestIndex] = min(abs(A-V))
closestValue = N(closestIndex)
Note that if there is a tie for the minimum value in each column, MATLAB chooses the first element in the column.
  댓글 수: 4
Adrian Aquino Arriaga
Adrian Aquino Arriaga 2021년 10월 8일 15:30
Great answer. I would only use dot-apostrophe (.') instead of only apostrophe to make sure you are taking the non-conjugate transpose. Of course, this is only relevant if you are working with complex numbers.

댓글을 달려면 로그인하십시오.

추가 답변(3개)

Andrew Reibold
Andrew Reibold 2014년 8월 25일
편집: Andrew Reibold 2014년 8월 25일
This finds the value in N which is closest to the V value I am calling.
N = [1990 1998 2001 2004 2001]
V = [2000 2011 2010 2001 1998]
[c index] = min(abs(N-V(1)))
In this case Im looking for the closest value to 'V(1)' which is 2000. It should return the 3rd or 5th value of N which is 2001.
Note: 'index' is the index of the closest value. If two are the same, like in this example with two different '2001's, it will return the index of the first one.
  댓글 수: 4
Image Analyst
Image Analyst 2018년 2월 17일
reetu, if N is just a single number then you can do this
[minDistance, indexOfMin] = min(abs(V-N));

댓글을 달려면 로그인하십시오.


Image Analyst
Image Analyst 2014년 8월 25일
How about this:
clc;
% Sample data
numberOfRows = 5;
V = rand(numberOfRows, 1)
N = rand(numberOfRows, 1)
% Find min distance
minDistance = inf;
for ni = 1 : numberOfRows
for vi = 1 : numberOfRows
distances(vi, ni) = abs(N(ni) - V(vi));
if distances(vi, ni) < minDistance
minNRow = ni;
minVRow = vi;
minDistance = distances(vi, ni);
end
end
end
% Report to command window:
distances
fprintf('Closest distance is %f which occurs between row %d of N and row %d of V\n',...
minDistance, minNRow, minVRow);
In the command window:
V =
0.5309
0.6544
0.4076
0.8200
0.7184
N =
0.9686
0.5313
0.3251
0.1056
0.6110
distances =
0.4378 0.0005 0.2057 0.4252 0.0801
0.3142 0.1231 0.3293 0.5488 0.0435
0.5610 0.1237 0.0825 0.3020 0.2033
0.1487 0.2886 0.4948 0.7144 0.2090
0.2503 0.1870 0.3932 0.6127 0.1074
Closest distance is 0.000470 which occurs between row 2 of N and row 1 of V
  댓글 수: 3
Image Analyst
Image Analyst 2017년 11월 10일
What's wrong with a for loop? And what is ni and vi?

댓글을 달려면 로그인하십시오.


Eswar Aravind Swamy Adari
Eswar Aravind Swamy Adari 2019년 5월 1일
Hi,
I have a matrix A of size [30x36] and B of size [38x36]. How do I find the closest pairs?
FYI- Those are the HOG Descriptors of block size 16x16 and cell size 8x8. I am trying to find the closest HOG descriptors.
Thanks in advance.

Community Treasure Hunt

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

Start Hunting!

Translated by