Filter löschen
Filter löschen

Replacing matrix A with another matrix that counts entries from matrix B

1 Ansicht (letzte 30 Tage)
Sorry for the confusing title and I will explain everything below.
I would like something that does the following (better if loops are not used): A code that replaces the entire matrix A (size unknown but all entries are unique integers) by counting the number of same entries as A has from matrix B (size unknown, all integers, might have redundant entries).
Example.
Input is A = [1 3 5; 6 4 11]; B = [3 3 2 1 4 6 10 29; 4 2 1 1 99 1 7 29; 8 2 1 6 7 6 11 1]
After using the code to replace A, the output should be A = [6 2 0; 3 2 1]; (since there are 6 of number 1, 2 of number 3, no number 5, 3 of number 6, 2 of number 4 and only one of number 11).
Thanks very much for your help. Please let me know if you have any questions.

Akzeptierte Antwort

Azzi Abdelmalek
Azzi Abdelmalek am 2 Jun. 2013
Bearbeitet: Azzi Abdelmalek am 2 Jun. 2013
A = [1 3 5; 6 4 11];
B = [3 3 2 1 4 6 10 29; 4 2 1 1 99 1 7 29; 8 2 1 6 7 6 11 1]
A=arrayfun(@(x) sum(sum(ismember(B,x))),A)

Weitere Antworten (2)

Image Analyst
Image Analyst am 2 Jun. 2013
I hope this isn't your homework or you can't turn this in:
% Sample data:
A = int32([1 3 5; 6 4 11])
B = int32([3 3 2 1 4 6 10 29; 4 2 1 1 99 1 7 29; 8 2 1 6 7 6 11 1])
% Now get the histogram.
edges = unique(A(:))
counts = histc(B(:), edges)
In the command window:
A =
1 3 5
6 4 11
B =
3 3 2 1 4 6 10 29
4 2 1 1 99 1 7 29
8 2 1 6 7 6 11 1
edges =
1
3
4
5
6
11
counts =
9
2
2
0
7
1
  4 Kommentare
Alex
Alex am 2 Jun. 2013
Dear predecessors, I am a beginner to matlab. Recently i am studying a thesis about my major, in which matlab is used. Something goes wrong while repeat the process of the thesis and i can't find a solution or help from my friends. Would you kindly take a few mins to have a look my question and give me some sugguestion? This is my question: http://www.mathworks.com/matlabcentral/answers/77715-how-to-find-the-polynomial-coefficients-of-two-array
Many thinks!
Image Analyst
Image Analyst am 2 Jun. 2013
Sorry - forgot to eliminate the elements in B that weren't in A so the 2's got counted. Try this code:
% Sample data:
A = int32([1 3 5; 6 4 11])
B = int32([3 3 2 1 4 6 10 29; 4 2 1 1 99 1 7 29; 8 2 1 6 7 6 11 1])
% Eliminate elements of B that aren't in A.
inA = ismember(B(:), A(:))
B = B(inA);
% Now get the histogram.
edges = unique(A(:))
counts = histc(B(:), edges)
Results:
counts =
6
2
2
0
3
1

Melden Sie sich an, um zu kommentieren.


Andrei Bobrov
Andrei Bobrov am 2 Jun. 2013
[ii,jj] = ismember(B,A);
out = reshape(accumarray(jj(ii),1),size(A));

Kategorien

Mehr zu Creating and Concatenating Matrices finden Sie in Help Center und File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!

Translated by