Made with matplotlib:

#!/usr/bin/env python

from pylab import *

rc('grid', color='#aaaaaa', linewidth = 1, linestyle = '-')
rc('xtick', labelsize=0)

figure(figsize = (20, 20))
ax = axes([0.1, 0.1, 0.8, 0.8], polar = True)

t = arange(-4 * pi, 4 * pi, .01)
polar(t, 1.19**t, linewidth = 2)

savefig('logarithmic_spiral.svg')