have been practicing questions i see online i just cant get how to solve this mathwork

Write a function called flip_it that has one input argument, a row vector v , and one output argument, a row vector w that is of the same length as v. The vector w contains all the elements of v, but in the exact opposite order. For example, if v is equal to [1 2 3] then w must be equal to [3 2 1]. You are not allowed to use the built-in function flip, fliplr, or flipud.

[KSSV]

Whjat have you attempted for this simple home work?

Hint: Run a loop in reverse.

[DGM]

I will note that they didn't explicitly say you couldn't use flipdim().

But I suppose that's not good enough.

Consider a vector

v = [12 35 48 63];

it has the linear indices:

idx = 1:numel(v);

Suppose you did this instead:

idxr = numel(v):-1:1;

What would happen if you used those indices to address v?

[Sam Chak]

Do you think that sort is easier for you to rearrange the elements?

sort()

Answer 1

[Chandrika]

As per my understanding, you need to code for a function that reverses a vector. You can do this using a recursive function. Please try the following code:

function w=flip_it(v) 
    w=[];
    if isequal(length(v),1)
        w=v(1);
    elseif length(v) > 1
        st=v(1:ceil(length(v)/2));     
        ed=v(ceil(length(v)/2)+1:end);              
        w=[flip_it(ed) flip_it(st)];
    else
        return
    end         
end

Here, recursion stops when length of the vector is 1, else flip_it function keeps getting called as part of the recursion.