Add a number(specific column) to vector without deleteing it.

I have an vector

a= [1 2 3 4 5 6 7 8]

How can I add 2.5 into the vector a at any location( in this example I want it to be at column2)

so that the result will be:-

p/s: not replace , the length increases

a= [1 2.5 2 3 4 5 6 7 8]

Answer 1

[KSSV]

a= [1 2 3 4 5 6 7 8] ;
b = 2.5 ;   % number to insert 
pos = 2 ;   % position at which number to be inserted
b = [a(1:pos-1) b a(pos:end)]

[fyza affandi]

Thank you

Answer 2

[dpb]

One of many possible ways...

insertat=2;
val=2.5;
a=[a(1:insertat-1) val a(insertat:end)];

The key is to not store into the new array until the construction is done so don't change locations of expression RHS of assignment statement.

[fyza affandi]

Thank you

Answer 3

[madhan ravi]

Another possibility:

a=1:8;
b=zeros(1,numel(a)+1);
insert_position=2;
b(insert_position)=2.5;
b([1 insert_position+1:end])=a(:)

[fyza affandi]

Thank you