loops

Hello,

I have the following problem in Matlab: Consider dataset a, with the following two columns:

0 / 0

0 / 0

1 / 0

1 / 0

1 / 9

0 / 0

-1 / 0

-1 / 4

0 / 0

My problem is that the value 9 has to be spread equally during the time that column 1 is equal to 1. The same has to be done with the value 4 during the time that column 1 is equal to -1. The result I have to obtain is the following:

0 / 0

0 / 0

1 / 3

1 / 3

1 / 3

0 / 0

-1 / 2

-1 / 2

0 / 0

Thanks,

Pieter

[Oleg Komarov]

What have you done so far?

Answer 1

[the cyclist]

Guessing this is homework, but not sure, so I will give you a solid kick in the right direction. Here is part of what you need to do, with a lot of assumptions about things you were not specific about.

A = [0 0; 0 0; 1 0; 1 0; 1 9; 0 0; -1 0; -1 4; 0 0];

indexToOnes = (A(:,1)==1);

numberOfOnes = sum(indexToOnes);

valueToDistribute = max(A(indexToOnes,2));

A(indexToOnes,2) = valueToDistribute/numberOfOnes

It does not handle the -1 part, which maybe you can figure out for yourself.

Answer 2

[Oleg Komarov]

A = [0 0
     0 0
     1 0
     1 0
     1 9
     0 0
    -1 0
    -1 4
     0 0];

A(3:5,2) = 3;
A(7:8,2) = 2;