How to change the length and the values of a vector?

I have a vector whose length = 503. I want to obtain a vector whose length is 100 or its multiple. I suppose I have to use some proportion, but I don't know how.

I think also the values of vector must change, but in which way? I think with the mean.

[madhan ravi: removed huge amount of data]

Answer 1

[madhan ravi]

n = numel(vector);
V = reshape([vector, nan(1, 1e2 - mod(n, 1e2))], [], 1e2);

Wanted = nanmean(V) 
%or
Wanted = mean(V, 'omitnan') 

%% or depending on which suits you the best
V = reshape([vector, nan(1, 1e2 - mod(n, 1e2))], 1e2, []);

Wanted = nanmean(V, 2) 
%or
Wanted = mean(V, 2, 'omitnan') 

[Enrica Brunetti]

Thank you very much, but I want to avoid having 'NaN' in the last values, while leaving the vector length unchanged, so the vector must have 100 values, other than zero and 'Nan'.

[madhan ravi]

So , what do you propose?

[Enrica Brunetti]

Is there any way to obtain the average within 100 values?

Or is it correct if I use the function imresize( vector, [1 100]);? In this way I get a vector of 100 values, even if I don't understand with which operations it obtains them.