set output 'pend_data_c.ps' 
set term postscript color enhanced 'Helvetica,18'  
set grid 
set key top left 
set ylabel 'Square of angular frequency (rad/s)^2' 
set xlabel 'Reciprocal of length (1/meter) ' 
set title 'Classroom measurements of pendula '
plot [0:10.5][0:110] 'calc_pend_graph.out' using 2:4:3:5     with xyerrorbars     lt 1 pt 3 lw 3 t ''  ,  9.44*x+0.045 with lines lc 3 lt 1 t '9.54 m/s^2'  ,  9.94*x+0.045 with lines lc 4 lt 1 t '9.94 m/s^2'  
set output 
quit 
