#set terminal postscript eps color
#set output "xlinear.eps"
L=1.0
omega(k) = k*pi/L
set xrange [-L:L]
t(x,k) = -2/omega(k)*(-1)**k*sin(omega(k)*x)
series(x,n) = (n>0 ? t(x,n) + series(x,n-1) : 0)
plot series(x,10),x