Insert a blank column every n columns

Hi. I have a matrix (size 10x360) and I want insert a blank column every n columns. How can I do? I have tried to use for loop, but unsuccessfully.

Thanks, Alessandro

Answer 1

[Carlos]

Try this, if you want to insert a blank column every 5 columns

 A=rand(10,360);
 A=num2cell(A);
 A(:,1:5:end)=cell(1);

[Alessandro Innocenti]

It doesn't work...it deletes the column, it does not insert a blank column.

[Carlos]

OK, I misunderstood your question, look at the file exchange function insertrows uploaded by Jos, that http://www.mathworks.com/matlabcentral/fileexchange/9984, that may do the job for you.

Answer 2

[Peter]

To insert columns with zeros you can try this:

A=rand(10,360);
n = 5;
nc = floor(360/n);
for c=1:nc;
    B(:,(n*c+c-n):(n*c+c-1)) = A(:,(n*(c-1)+1):n*c);
end

If you need empty cells, you can convert your matrix to a cell array like Carlos showed before.

Answer 3

[Andrei Bobrov]

yourmatrix = randi(23,10,360);
n = 6;
yourmatrix(:,n:n:end) = nan;

or

a = randi(23,10,360);% your matrix
n = 5;
s = size(a);
k = floor(s(2)/n);
n1 = k*n;
out = [reshape([reshape(a(:,1:n1),s(1),k,[]),...
                            repmat(nan,[s(1),1,n])],s(1),[]),a(:,n1+1:end)];

or

a = randi(32,10,360);
n = 7;

out = zeros(s+[0 floor(s(2)/n)]);
out(:,n+1:n+1:end) = nan;
out(~isnan(out)) = a;

Answer 4

[dinesh wankhede]

i have matrix a with some rows and some columns i want matrix b with same number of rows but double the number of columns such that every column repeats itself

[Walter Roberson]

kron(a, [1 1])

Answer 5

[minhua su]

this is how i solved the problem recently

str = strings([1,508*7])

i=[]

j=1

for i=1:508

str(j)=bamfiles(i)

j=j+7

end

[minhua su]

bamfiles is my original matrix, which is (size 1X508), and i create a new matrix str (the size is decided by how many every columns you want to insert)