MATLAB: How to replace the elements row by rows instead of column by column in matrix

MATLABmatrix arraymatrix manipulation

A =[ 0 0 3 3 3 0 0 3 0 0; 0 0 0 3 3 3 0 3 3 0]
[rows,colms ] = size(A)
for i = 1:rows
    for j = 1:colms
            index-1 = find(A==3,1,'first')
            index_2 = find(A==3,1,'last')
                    If     A(i,j)=3 & A(i,j)==index_1
                           A(i,index_1:index_2) = A(i,index_1:index_2) +1
                    end 
    end 
end
it gives me 5th and 18th indices while i want to get row wise like first should be 3rd and last should be 6th.
please help me in resolving this problem.
warm regards in advance.

Best Answer

find(A==3,1,'first')
find(A==3,1,'last')
These lines find linear indices not [row, col] subsets. Linear indices go along all the rows of the first column, then on to the second column and so on.
These two lines also disregard i and j completely, so they always give the absolute first and last linear indices in the entire matrix each iteration (5 and 18).
I dont know what exactly you're trying to achieve, but maybe you need to compare only current row:
index_1 = find(A(i,:)==3,1,'first');
index_2 = find(A(i,:)==3,1,'last');
Look here for explanation on array indexing in Matlab
if A(i,j)=3 & A(i,j)==index_1
This condition compares the value of A(i,j) to 3 and to the first index which equals 3, that makes little sence to me, but i may be missing your intent
If you explain with more detail what you are trying to do, we may be able to help you get to the right solution
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