How to pass control from one loop to the other loop

My aim is to alter a data sample in such a way that the sign of values in between 0.01 to next 0.01 are altered.

Like for example; if given sample is

 {0.3,0.21,0.9,0.3,0.01,0.3,0.4,0.32,0.01,0.9,0.97}

My code has to give the output as

 {0.3,0.21,0.9,0.3,0.01,-0.3,-0.4,-0.32,0.01,0.9,0.97}

So, I'm trying to write a nested loop to read the sample and alter the sign in between 0.01 to next 0.01

    for n=1:100000
        if u(n)=0.01
           for m=n+1:10000
               if u(m)=0.01
                  % switch to the original 'n' loop
               end
               u(m)=-1*u(m);
           end
        end
    end

But, I'm unable to switch to the original loop. Anyone suggest, how can I switch between them ?

Answer 1

[Thorsten]

invert = 1;
for i = 1:numel(u)
  if u(i) == 0.01
    invert = -invert; 
  elseif invert<0
    u(i) = -u(i); 
  end
end

[Sai]

Thanks for your answer, very simple and elegant :)

Answer 2

[Eng. Fredius Magige]

try this

for n=1:100000 if(find(sample(:)==0.01,1)=<find(sample(:)==0.01,2)) % sample is your data num=-1*sample(:,n) else num=sample(:,n) end

[Sai]

Thanks for your suggestion :). It worked

Answer 3

[Stephen23]

There is no need for slow and inefficient loops when code vectorization is faster and neater:

>> tol = 0.0005;
>> val = 0.01;
>> V = [0.3,0.21,0.9,0.3,0.01,0.3,0.4,0.32,0.01,0.9,0.97];
>> idx = abs(V-val)<tol;
>> idy = mod(cumsum(idx),2);
>> idz = (-1).^(idy&[false,idy(1:end-1)]);
>> V.*idz
ans =
       0.3  0.21   0.9   0.3  0.01  -0.3  -0.4 -0.32  0.01   0.9  0.97

[Sai]

Thanks for your answer, You've introduced me to new concept. :)

[Stephen23]

My pleasure. You can also vote for answers that introduce you to new concepts!