set style data lines

plot \
'z.LogBarrier' us 2:3,'' us 2:4,\
'z.AnyTimeAugmentedLagrangian' us 2:3,'' us 2:4,\
'z.AugmentedLagrangian' us 2:3,'' us 2:4,\
'z.SquaredPenalty' us 2:3,'' us 2:4
