indexing of starting element of sum

function [summa,index=nba_aj(b,n)                                                         
s=length(b);
i=0;
if n>s
    a=0
    k=-1
elseif n<=s
   q=movsum(b,n)
    summa=max(q)

what should i do after this for index finding

% here i want to know the index

can you guys help me the required answer is

summa=13,index=4      b=[1 2 3 4 5 4 3 2 1] n=3
                                                                                                     summa=5,index-5        b=[1 2 3 4 5 4 3 2 1] n=1

[Walter Roberson]

This is being discussed in https://www.mathworks.com/matlabcentral/answers/444784-write-a-function-called-max_sum-that-takes-v-a-row-vector-of-numbers-and-n-a-positive-integer-as

[asad Jaffar]

Yeah but no answer yet , please take a look at this No ,its not about the index of maximum number in an array,its about starting index of maximum sum for example ([1 2 3 4 5 4 3 2 1]9) this is the example of above question mentioned and the answer is summa=25 ,index= 1. The algorithm is that a=movsum(v,n) Summa=max(a) Now if i found index of max it will give 5,but it should be 1 because it starts with 1 in an array. Another example ([1 2 3 4 5 4 3 2 1],3) Summa=13,index = 4 Now max is 5 in array but index in answer is 4 its about starting of number of sums 4+5+4=13 index of 4 in sum is 4 , kindly help me with this index thing ,give hint.

[Jan]

As Walter has said already: This topic has been discussed already and you find a working solution there also. All you need is reading the documentation of movsum:

doc movsum

and to learn, why you have to ignore the marginal elements by setting 'EndPoints' to 'discard'. In addition you have to use the 2nd output of max.

Pleae note that posting working solution of homework questions is not really useful.