from numpy import *
from matplotlib import pyplot as py

r = zeros([16])
err = zeros([16])
for i in range(16):
    r[i] = random.randint(400, 600)
    err[i] = random.randint(20, 50)
theta = arange(0, 2 * pi, 2 * pi / 16)
width = pi * 2 / 16

fig = py.figure(figsize=(8, 8))
ax = fig.add_axes([0.1, 0.1, 0.75, 0.79], polar=True)

bars = ax.bar(
    theta + pi / 16,
    r,
    width=width,
    bottom=0.0,
    yerr=err,
    capsize=15 # Capsize set to exaggerate issue
    )  
ax.set_ylim(0, 700)

ax.set_theta_direction(-1)  # Clockwise direction

py.show()

from numpy import *
from matplotlib import pyplot as py

r = zeros([16])
err = zeros([16])
for i in range(16):
    r[i] = random.randint(400, 600)
    err[i] = random.randint(20, 50)
theta = arange(0, 2 * pi, 2 * pi / 16)
width = pi * 2 / 16

fig = py.figure(figsize=(8, 8))
ax = fig.add_axes([0.1, 0.1, 0.75, 0.79], polar=True)

bars = ax.bar(
    theta + pi / 16,
    r,
    width=width,
    bottom=0.0,
    yerr=err,
    capsize=15 # Capsize set to exaggerate issue
    )  
ax.set_ylim(0, 700)

ax.set_theta_offset(np.pi/2)  # Start from the top

py.show()