Inserting a column in an matrix array

Hi guys,

I would like to write a code to insert the column insert a whole column in an array as in a following example:

q=[1 2 3 4, 5 6 7 8, 9 10 11 12, 13 14 15 16, 17 18 19 20];

for example:

i1=2

i2=4

I want to insert the second column after the fourth but I don't wan't to see the second one at the second place, so then I would have 1 3 4 2 columns in this order. Here in my code it inserts randomly picked column but then the column is in both places and q new has one column more.

i=randsample(n,2) %randomly picking two columns
i1=i(1);
i2=i(2);
v=q(:,i(1));
qnew = [q(:,1:i(2)) v q(:,i(2)+1:end)]

Answer 1

[Monica Roberts]

You could just delete the duplicate column you don't want anymore:

qnew = [q(:,1:i2) v q(:,i2+1:end)];
if i1<i2
    qnew(:,i1)=[]
else % original column shifted when added new column
    qnew(:,i1+1)=[]
end