FOR LOOP, add value to each row at a time

Hello!

I have a column vector X size (26x1) which has 26 different values. In the FOR loop, I want to add a small value to each row (one at a time) at each step.

For example:

for n=1:1:length(X)

value(n) = 1

X plus = X + value(n)

end

I find that this code adds [value] to every row which is not what I want. It should be:

X plus = [ 1+value,1,1,1,1..]' % at step 1

X plus = [1, 1+value,1,1,1,...]' % step 2

X plus = [1,1,1+value,1,1...]' % step 3

and so on...

It should maintain the original values and only add value to the corresponding row as determined by n. Any help is appreciated, thanks!

[dpb]

MATLAB addresses variables not subscripted as the entire array; if you want to only address a portion of an array, you must use the desired subscript for the element(s) wanted.

In this case that would be

Xplus(n)=...

Also as written "X plus" is not a valid variable name; no embedded spaces are allowed and you should also preallocate arrays.

Answer 1

[Jan]

X = ones(1, 10);
for n = 1:size(X, 2)
    Y    = X;  % Copy original value
    Y(n) = Y(n) + 1;
    ... do what you want to do with Y
end

Or:

X = ones(1, 10);
for n = 1:size(X, 2)
    Xback = X(n);
    X(n)  = X(n) + 1;
    ... do what you want to do with X
    X(n) = Xback;  % Restore original value
end

[Nadia Numa]

Thank you!