elongation_al(eps_almansi) = 1./sqrt(1. - 2.*eps_almansi)
eps_log(eps_almansi) = log(elongation_al(eps_almansi))

ep0 = 0.5
NU_12 = 0.79
NU_13 = 0.2

set xlabel "eps11 log"
set ylabel "eps 22 ou 33 log"
set xrange[0:]
set grid
p   "test_princ.maple" u (eps_log($5)):(eps_log($6)) t 'eps 22' w p pt 4 lc 1
rep "test_princ.maple" u (eps_log($5)):(log($21/ep0)) t 'eps 33 (via epaisseur)' w p pt 4 lc 3
rep -NU_12*x t 'th NU 12='.sprintf("%.5f", NU_12) w l lc 1 dt 2 lw 2
rep -NU_13*x   t 'th NU 13='.sprintf("%.5f", NU_13) w l lc 3 dt 2 lw 2
pause -1
