%matplotlib inline
matplotlib.pyplot.errorbar(x, y, yerr=None, xerr=None, fmt='-', ecolor=None, elinewidth=None, capsize=3, barsabove=False, lolims=False, uplims=False, xlolims=False, xuplims=False, errorevery=1, capthick=None, hold=None, **kwargs)
import numpy as np
import matplotlib.pyplot as plt
f = [822, 693, 547, 518]
y = f
v = [1.7, 1.28, .67, .395]
df = np.array([.5, 5, 2, 1])
dv = np.array([.01, .01, .01, .05])
fit = np.polyfit(v, f, deg=1)
def f(x,fit): return fit[0] * x + fit[1]
xfit = np.linspace(0,2)
plt.errorbar(v, y, yerr=df, fmt=".k")
plt.plot(xfit, f(xfit, fit))
[<matplotlib.lines.Line2D at 0x7f94d1fe44a8>]