How can I plot two vectors of different lengths ?

I am given a vector A with size(A) = 41,1 and a vector B with size(B) = 40,1 I want create a plot with B on the y-axis and A on the x-axis. But each entry of vector B should be associated to the midpoint of two entries of vector A. So for example: A(1) = -30, A(2) = -29. In the plot I want A_plot(1) = -29.5

How can I achieve this? I was thinking about:

sz1 = size(A);
for n = 1:(sz1(1)-1)
    A_plot(n) = (A(n)+ A(n+1))/2;
end

But the result is a vector of size 41,41

Answer 1

[Stephen23]

 A_plot = (A(2:end)+A(1:end-1)) / 2;