Negative scale on a Y log scale waveform graph.

[GAP]

I have a problem with my waveform graph : I would like to set Y negative scale in a logarithmic mode. How can I do that? It seems to be impossible (always set to '0' if a set negative value)! What is the problem ?
Thank's in advance.

[Gorka Larrea]

The reason is simple, logarithmic values cannot be negative, as logarithm is asintothic in zero, this means log 0 has a value of -inf. So what you want is impossible.

[Enrique]

Well, I am sure what you wanted to say is that the argument of the logarithm must be positive. In other words:

y = log(x); x should be positive.

If you want "y" to be negative, then 0 < x < 1

[Gorka Larrea]

I mean that if you set y axis scale as logaritmic, you can't put negative values, it will allways have a zero as start as long as it can't be beyond that.

[Mike Manzheliy]

Hi,
no problem,
see attached file.
Regards
Mike

GAP wrote:

> I have a problem with my waveform graph : I would like to set Y
> negative scale in a logarithmic mode. How can I do that? It seems to
> be impossible (always set to '0' if a set negative value)! What is the
> problem ?
> Thank's in advance.