Summation of two vectors over a range

I have to write a code in Matlab for adding the following two vectors

with .

The elements corresponding to and are the boundary elements. So

if the values of the vector are chosen as

(say)

and with boundary conditions at both ends, I wrote the code, but there's a dimensions mis-match later on. So I was

thinking maybe I wrote something wrong in the code for the addition of the two vectors above.

The code I wrote to implement this vector addition is

maxm=5;
X = [-4, -6, -13, -9, -16]
BConleft=X*exp(-3*i);
BConright=X*exp(-3*i);
sumneighborsX = [X(2)+BConleft,diff(X,2)+2*X(2:maxm-1),X(maxm-1)+BConright]

[madhan ravi]

give an example of your desired result

[Irfan ahmed]

just the summation should be a valid one.

[Irfan ahmed]

The values are taken as [-1,-2,-3,-4,-10,-5,-6] to create X by summations

[AtoZ]

@madhan probably the question isn't very clear. I will try to post it in a more clear way.

Answer 1

[Image Analyst]

Looks like you're trying to do a convolution:

sumOfNeighborsX = conv(X, [1,0,1], 'full');

Are you?