Check difference between two vectors

[shapper]

Hello,

Is it possible given two vectors, A and B, create a third vector, C,
using the following conditions, without a loop?

D = A - B

If D(i) * D(i-1) < 0 and D(i) 0 then C(i) = 1

If D(i) * D(i-1) < 0 and D(i) < 0 then C(i) = -1

If D(i) * D(i-1) 0 then C(i) = 0

---

If D(i) * D(i-1) = 0 then

If D(i) * D(i-2) < 0 and D(i) 0 then C(i) = 1

If D(i) * D(i-2) < 0 and D(i) < 0 then C(i) = -1

If D(i) * D(i-2) 0 then C(i) = 0

end

Basically I am creating a function that detects when a function
crosses under or over another function or a constant level ...

This was what I came up with ...
.... the second part is because sometimes the values can be equal
before the cross occurs ...

I am trying to make this with vectors.

Thank You,
Miguel

[shapper]

On Feb 15, 4:36 pm, shapper <[e-mail]:

Hello,

Is it possible given two vectors, A and B, create a third vector, C,
using the following conditions, without a loop?

D = A - B

If D(i) * D(i-1) < 0 and D(i) 0 then C(i) = 1

If D(i) * D(i-1) < 0 and D(i) < 0 then C(i) = -1

If D(i) * D(i-1) 0 then C(i) = 0

---

If D(i) * D(i-1) = 0 then

If D(i) * D(i-2) < 0 and D(i) 0 then C(i) = 1

If D(i) * D(i-2) < 0 and D(i) < 0 then C(i) = -1

If D(i) * D(i-2) 0 then C(i) = 0

end

Basically I am creating a function that detects when a function
crosses under or over another function or a constant level ...

This was what I came up with ...
... the second part is because sometimes the values can be equal
before the cross occurs ...

I am trying to make this with vectors.

Thank You,
Miguel

Ooops, forget it. I posted this on the wrong group.

Sorry,
Miguel