更改gnuplot中的条形图案

Question

如何更改最后一列的模式？ 这是脚本：

set ylabel "Accuracy"
set style fill solid border
set style line 1 lt 1 lc rgb "blue"
set style line 2 lt 1 lc rgb "green"
plot "orientation.csv" u (column(0)):2:(0.5):($2!=0.875?1:2) title "" w boxes lc variable fs pattern 1;