Re: log plotting

[Ansley Manke <ansley@xxxxxxxxxxxxx>]

Hi Richard,
This behavior lies within the underlying PPLUS graphics code.  In the
next version of Ferret (version 5.4) we are adding new  plot qualifiers
/VLOG  and /HLOG which make it easier to set up log axes, but this
change doesn't affect the fact that log axes are drawn with integer number
of decades.

Perhaps somebody will have a fancy work-around but this is how things
stand at present.

Ansley Manke


"Richard D. Slater" wrote:

> Ferret 5.22, intel, linux
>
> I am having a problem doing log plots, or rather adjusting the axis range. I
> wish to do a semi-log plot where the y-axis is log scale, and the x-axis is
> linear. Following the log_plot_demo,jnl, everything works fine. However,
> ferret (or pplus) uses full orders of magnitude when picking axis limits and
> labeling them. This is not satisfactory for what I am plotting as the data has
> a range of much less than two orders of magnitude (what ferret picks for the
> plot).
>
> The values that I am plotting range between 0.4 and 2.5. When I used these
> numbers for the vlimit= specifier, the results were not as anticipated. The
> range of the y-axis was really 10^0.4 to 10^2.5, but the axis labels were
> still two orders of magnitude, going below the lower horizontal axis, and not
> reaching the top horizontal axis. OK, I figured, even though the data given to
> the plot command is not the log, the vlimit must already be the log. So, I
> changed the limits to -0.4:0.4, and now ferret crashes.
>
> Any ideas?
>
> Thanks,
>
> Rick Slater

--
Ansley Manke  Pacific Marine Environmental Laboratory  Seattle WA  (206)526-6246