On Wed, Jul 25, 2012 at 11:26 AM, Michele Minelli <micheleminelli1 at gmail.com
> wrote:
> Hi everyone,
> I was trying to plot y=abs(log(x)) with
>
> *plot2d(abs(log(x)), [x, -10, 10]);*
>
> and I realized that Maxima plots a curve even for x less than zero. Could
> someone explain me why (I remember reading it once but I couldn't find it
> anymore) and how to disable this representation if I want?
>
Not exactly sure what you're referring too here, but log is defined for
negative values of x. In fact log(-x) = log(x) + %i*%pi when x < 0. So
abs(log(x)) is also a nice number.
The easy answer is just to plot from 0 to 10 instead of -10 to 10, since it
looks like you don't want that part. Or maybe something like:
plot2d('(if is(x<0) then inf else abs(log(x))),[x,-10,10]);
There are probably better ways to do this.
Ray