set output 'fall2015.ps' 
set term postscript color enhanced 
set grid 
set key top right 
set ylabel 'Period SQUARED (seconds-squared) 
set xlabel 'Length of pendulum (cm)' 
set title 'pendulum experiment Nov 16, 2015' 
plot [-10:160] 'fall2015_pend.dat' using  ($1):($2*$2):($2*$2)*(2*($3/$2))  with yerrorbars  lt 1 pt 1 lw 4 t ''  
set output 
quit 
