Re: yrange log-function

On 2005-12-10, Hans-Bernhard Broeker <broeker@xxxxxxxxxxxxxxxxxxxxx> wrote:
> Uwe Bieling <a.1.psychi0913@xxxxxxxxxxxxxxx> wrote:

Hi,

> You're overdoing things (in German: doppelt gemoppelt).

Yes. I didn't saw the wood for the trees.

>
>> But i get always the same error. "y2 range must be greater than 0 for
>> log scale." There are no negative x-values in the data file, also no zero
>> value.
>
>> Where is the mistake? The log function has no restriction in the y
>> range.
>
> But of course it does! log(negative) is completely undefined, log(0)
> is minus infinity.

Sorry, that i don't understand. log is definied in the xrange (abscissa) from
zero to plus infinity, the corresponding y-values are minus infinity for zero
and plus infinity for plus infinity. Where are the restriction in the
yrange, which is defined from minus to plus infinity? The log function
is only restricted in the xrange.

(xrange [0:+oo] yrange [-oo:+oo])

Or - as longer i think about this - does Gnuplot calculate the range
with the to arugments beetween the brackets? Then a value below zero is
not definied, zero means infinity and beetween 0 and 1 negative
y-values. I thought, that the arguments are directly for the axes:
yrange [-5:5] should result in labeled axes from -5 to 5, even in
logscale.

Thanks,
Uwe
.

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