# paste this code at the end of VectorFieldPlot 1.0
doc = FieldplotDocument('VFPt_wires_parallel_out', width=800, height=600, commons=True)
field = Field({'wires':[[-1.5,0,1], [1.5,0,1]]})
doc.draw_currents(field)
r0 = 0.19
r1 = 2.75
n = 8
for i, sign in [[j, 1] for j in range(n)] + [[j, -1] for j in range(4)]:
    r = r0 * pow(r1 / r0, i / (n - 1.))
    if i == 0: r = -r
    line = FieldLine(field, [(1.5 + r) * sign, 0], directions='both')
    doc.draw_line(line, arrows_style={'dist':1.9, 'min_arrows':1,
        'max_arrows':8, 'offsets':[0.0, 0.5, 0.5, 1.0]})
doc.write()