recording matrix increasing in another matrix.

Hi friends,

I have a simple question,

A = [0.8888 0.5555 0.4444 0.7777 0.6666 0.2222 0.9999 0.1111];

B = 0.1;

While S=size(C,1) C=A+B; S=sum(C(:)>=1); B=B+0.1; end

in the above loop, the "C" will change to C=[0.9888 0.6555 0.5444 0.8777 0.7666 0.3222 1.0999 0.2111]; and then C=[1.0888 0.7555 0.6444 0.9777 0.8666 0.4222 1.1999 0.3111]; and then C=[1.1888 0.8555 0.7444 1.0777 0.9666 0.5222 1.2999 0.4111]; like this every element of C will cross 1,

i want D matrix to be recording which element first crossed 1 and which element second crossed 1,

like D=[2 5 6 3 4 7 1 8];

Please help i thanks in advance,

Jagadesh Rao Thalur

[Guillaume]

Can you edit your question to

1. format your code properly. Use the {} Code button or put two spaces before each line of code.
2. Fix the errors in your code so we can run it. Neither S nor C are declared before the start of the loop, so your while statement is invalid. It is doubly invalid because of the = (probably meant ==).

[Jagadesh Rao]

Am sorry Dear Guillaume

A = [0.8888; 0.8555; 0.8444; 0.8777; 0.8666; 0.7222; 0.8999; 0.4111];

C = zeros((size(A,1)),(size(A,2)));

S=0;

B = [0.01; 0.009; 0.008; 0.007; 0.006; 0.005; 0.004; 0.003];

C = A+B;

while S<size(C,1)

C=C+B

S=sum(C(:)>=1);

B=flipud(B)+0.001

end

first C will become

    1.0088
    0.9745
    0.9624
    0.9947
    0.9826
    0.8372
    1.0139
    0.5241

now i want D to be

    1
    0
    0
    0
    0
    0
    1
    0
after a while C will become

    1.0288
    0.9935
    0.9804
    1.0117
    0.9986
    0.8522
    1.0279
    0.5371

now i want D to be

    1
    0
    0
    2
    0
    0
    1
    0

after that C will become

    1.0428
    1.0085
    0.9964
    1.0287
    1.0166
    0.8712
    1.0479
    0.5581

i want D to be

    1
    3
    0
    2
    3
    0
    1
    0

like this i need up to the last C.

I hope now you can easily understand my problem.

THank you so much

Jagadesh

Answer 1

[Guillaume]

I'm not sure why you're using a loop. You can calculate D simply with:

A = [0.8888 0.5555 0.4444 0.7777 0.6666 0.2222 0.9999 0.1111];
B = 0.1;
k = (1-A)./B;
[~, order] = sort(k);
D(order) = 1:numel(A)

[Jagadesh Rao]

C will not increase like big numbers first, small numbers last.

Sometimes small numbers also can increase and reach 1.

I don't want to record according to big and small numbers, but which reaches value '1' first.

Please try thanks Jagadesh Rao Thalur

[Guillaume]

See my comment to your question.

Can you also clarify your comment above. If you continuously add the same constant to some numbers, they will reach 1 in the same order as their starting values (unless they start above one obviously). It can't be any different.

If you're not adding the same constant to all numbers, then change your example to reflect what you're actually doing.

Answer 2

[Guillaume]

Before the loop initialise D, and a counter

D = zeros(size(A));
counter = 0;

In your loop, after you've calculated C, add

counter = counter + 1;
D = D + (C >= 1 & ~D) * counter;

This will put counter in D if a value in C is above 1 and the corresponding value in D is still 0. That is once a value in C has been recorded in D, it's never going to be assigned a new value.