#
# Demonstrate using xrange and yrange to isolate polar quadrants
#
set polar
set grid r polar 30
set grid lt black lw .3
set tics scale 0.5
unset xtics
set ytics axis
set ytics 2
set border 0
set size square

unset title
unset key

set rrange [0:6.1]
set ttics 0,30 format "%g".GPVAL_DEGREE_SIGN font ":Italic"
set mttics 3

set multiplot layout 2,2 title "Polar Quadrants"

set xrange [-6.5:0]
set yrange [0:6.5]
set ytics offset 4
plot t lt 3 lw 2, -t lt 4 lw 2

set xrange [0:6.5]
set yrange [0:6.5]
set ytics offset -1 
replot

set rtics offset 0,2
set xrange [-6.5:0]
set yrange [-6.5:0]
set ytics offset 4
replot

set xrange [0:6.5]
set yrange [-6.5:0]
set ytics offset -1
replot

unset multiplot


Click here for minimal script to generate this plot