Re: Interesting bug: relative offset + log scale = problem

[Daniel J S. <dan...@ie...>]

Hans-Bernhard Br=F6ker wrote:

> The same way he can enter an increment for logarithmic tics: as a=20
> factor, instead of the usual summand.

OK, you say "factor".  Here is what I sent to Ethan and what I think you =
are saying:

...

That is

y_title =3D alpha * y_hist;

Then

 log(y_title) =3D log(y_hist) + log(alpha)

and right there the log(alpha) is the "offset" we are searching for.

Is THIS what the user is thinking of when saying offset?  I'm guessing no=
, because in all likelihood the user would never enter an "offset" (i.e.,=
 alpha) of zero and it should be invalid.  If that is how we compute "off=
set", then the user will typically be entering something like 1.1 or 1.05=
, etc.

...

You are saying that the code is then correct (except for moving the compu=
tation of x_offset and y_offset outside the loop for efficiency) and 0 is=
 an invalid user entry.  Perhaps we should have an error message:

  For logarithm scale, 0 is not a valid factor.  Try a factor of 1.

Dan