average vector over selected areas

I have two vectors, one working, the second sections that I need to average in vector 1

A = randi([5 10],1,548); 
B=  [102 105 204 99 ]
% what i need to do x=mean(A(1:B(1)) ; x=mean(A(B(1):B(2))

how do i do this?

Answer 1

[KSSV]

A = randi([5 10],1,548); 
B=  [1 102 105 204]
% what i need to do x=mean(A(1:B(1)) ; x=mean(A(B(1):B(2))
iwant = zeros(length(B)-1,1) ; 
for i = 1:length(B)-1
    if B(i) < B(i+1) ;
        iwant(i) = mean(A(B(i):B(i+1))) ; 
    else
        iwant(i) = mean(A(B(i):-1:B(i+1))) ; 
    end
end

[Lev Mihailov]

mean(A(B(i):B(i+1)))  
% B(1):B(1+1) = B(1):B(102) 
% % and if I have a value in the vector will be [5 200 5 104 6]

[Image Analyst]

Lev, what indexes in A do you want to average if B(i+1) is LESS than B(i)? Like 200 to 5, or 104 to 6? Do you want to take the mean of from 5 to 200 (the opposite order), inclusive? In other words, sort the numbers in ascending order first?

[KSSV]

Edied the answer.