MATLAB: Adding vector entry after each element

vector

This is a very basic question but how would I add the elements of a vector like so…:

x = [1,2,3,4,5,6];

ans = 3 6 10 15 21

Best Answer

x = [1,2,3,4,5,6];
y = cumsum(x)
y = y(2:end)  % To match your example....

Related Solutions

MATLAB: ‘closeness’ of multiple vectors

Is closeness a measure of how many entries match in matching positions? In this case:

closeness = @(x, y) nnz(x == y) / numel(x);
A = [1 2 3 4 5];
B = [1 2 3 4 5];
C = [6 7 8 9 10];
closeness(A, B)
closeness(A ,C)

If your vectors can have noninteger entries, then to mitigate against floating point errors you'd replace x == y with abs(x - y) < tol * abs(x) where tol is something small, like 1e-14.

MATLAB: How to vectorize vector indexing

Another approach:

% Data
A = [1  2  3  4;
     5  6  7  8;
     9 10 11 12];
c = [2 3 1];
%Extraction:
E = A((1:size(A,1))+(c-1)*size(A,1)).'

If size(A,1) is already known (say m=3), then the obvious simplification results...

E = A((1:m)+(c-1)*m).'

Best Answer

Related Solutions

MATLAB: ‘closeness’ of multiple vectors

MATLAB: How to vectorize vector indexing

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