How do I find the midpoint (or average) of every row in a matrix in increments of two?

I need to find the midpoint between every 2 points of every row of a matrix. I need a program that will do it all at once so I will not have to write out an individualized code for every increment that the midpoint is needed, especially since the matrices that I am working with the number of rows range from 38-174. ie if I had the matrix [a, A, AA, b] I need a program that will without writing 3 lines of code will give me the matrix [(a+A)/2, (A+AA)/2, (AA+b)/2] in one step.

The first program I had

Amidpt=NaN*ones(39,2);
Amidpt(2:38,1) = ((A(:,2)+A(:,2))/2);
Amidpt(2:38,2) = ((A(:,3)+A(:,3))/2);

but this gave me the same numbers as matrix A.

The second I tried was

Amidpt=NaN*ones(39,2);    
Amidpt(2:38,1) = ave(A(:,2));
Amidpt(2:38,2) = ave(A(:,3));

but this program just gave me the average of the whole column 36 times in rows 2:38.

Any help or ideas would be helpful,

Thank you

Answer 1

[Walter Roberson]

(A(:,1:end-1) + A(:,2:end)) / 2

[Elizabeth]

I just had to switch the rows with the columns but that worked perfectly. Thank you!