Can anyone tell me why I get the "unrecognized terminal option" when having
set output "out.pdf"
Is there any package that I need to install for gnuplot 4.4?
Have you set the terminal? The command
print GPVAL_TERMINALS
in gnuplot will list all the avialable terminals; if pdfcairo is in the list you should be good to go. In general before setting the output you need to set the terminal, e.g.
set terminal pdf
set output 'out.pdf'