Sum of previous 5 numbers

A=[2 3 4 5 6 7 8 9 10 8 5];

I want to calculate sum of 5 previous values for A(i)

so my new matrix should be like this

B=[0 2 5 9 14 20 25 30 35 40 42 ];

As there is no previous 5 value before A(1)=2 so B(1)=0, There is one value before A(2) and it is A(1). Therefore B(2)=A(1)=2. There are two values before A(3) so B(3)=2+3=5. For A(9)=10, previous 5 values are 5 + 6 + 7+ 8+ 9 so B(9)=35. How can I do this summation. Thanks for the help.

Answer 1

[Walter Roberson]

A=[2 3 4 5 6 7 8 9 10 8 5];
B=[0 2 5 9 14 20 25 30 35 40 42 ];
N = 5;
C = movsum([0 A(1:end-1)], [(N-1) 0])

C = 1×11

0 2 5 9 14 20 25 30 35 40 42

isequal(C, B)

ans = logical
   1

[Walter Roberson]

A=[2 3 4 5 6 7 8 9 10 8 5];
B=[0 2 5 9 14 20 25 30 35 40 42 ];
N = 5;
C = conv(A, [0, ones(1,N)]);
C = C(1:end-N)

C = 1×11

0 2 5 9 14 20 25 30 35 40 42

isequal(C, B)

ans = logical
   1

[Gokhan Kayan]

Thanks for the reply Walter Robenson, this is what I exactly want :)