# For a matrix with an unknown number of rows, how to find the number of rows n and transform it into n matrices.

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Wesley on 11 Dec 2020
Commented: Ameer Hamza on 11 Dec 2020
Wesley on 11 Dec 2020
B=A, expand into A=[A1 A2 A3 A4].

Ameer Hamza on 11 Dec 2020
Edited: Ameer Hamza on 11 Dec 2020
You can find the number of rows in a matrix using size()
data1;
n = size(data,1)
or height() [only in R2020b and later]
data1;
n = height(data)
The second part of your question about transforming it into a matrix is not clear.

Ameer Hamza on 11 Dec 2020
Edited: Ameer Hamza on 11 Dec 2020
I guess you are trying to do something like this
rows = data1(:,2);
cols = data1(:,1);
M = zeros(max(rows), max(cols));
idx = sub2ind(size(M), rows, cols);
M(idx) = 1;
Result
>> imshow(M)
Ameer Hamza on 11 Dec 2020
You can use maxk() to get two largest values. For example
maxk(data1, 2)
gives 2 highest values in both columns.

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