How to specify different range for multiple functions in the same plot

[Peng...@gmail.com]

Hi,

plot [0:10] x, [-10:10] -x

Suppose I want to plot two different functions with different xrange.
Is it possbile to do it in gnuplot directly, if know the explicit form
for each functions?

Or I have to right data for each function into files and plot from
these files?

Thanks,
Peng

[Steve Bickerton]

Hi PengYu,

> plot [0:10] x, [-10:10] -x

> Suppose I want to plot two different functions with different xrange.

You can do this with the ternary operator (see 'help ternary'). Try the
following (based on your example above):

set xrange [-10:10]
g(x,min,max)=( (x>=min && x<=max)? 1.0 : (1/0) )
plot x*g(x,0,10) with line, -x*g(x,-10,10) with line

If you're finding that the lines don't quite meet at the boundaries, try
increasing 'samples' to 200.

set samples 200

Hope that helps,
steve

[Hans-Bernhard Bröker]

Peng...@gmail.com wrote:

> Suppose I want to plot two different functions with different xrange.
> Is it possbile to do it in gnuplot directly, if know the explicit form
> for each functions?

Not quite.

> Or I have to right data for each function into files and plot from
> these files?

No. There are two alternatives:

1) plotting a function, but setting its value to "undefined" where you
don't want it plotted. See Steve Bickerton's earlier answer.

2) The generic "strange curve plotting cure": parametric mode

set parametric
set trange [0:1]
x1(t)=-10+10*t
x2(t)=-10+20*t

plot x1(t), f1(x1(t)) title "f1(x)", \
x2(t), f2(x2(t)) title "f2(x)"