`# trim the data
y = np.ones(PDF_x.shape)*PDF_x
y[y>95]= np.nan
y[y<75]= np.nan


# plot the data
fig = plt.figure()
ax = fig.gca(projection='3d')
for i in range(PDF_capacity.shape[1]):
    ax.plot(life[i]*np.ones((PDF_x.shape)),y,PDF_capacity[:,i], label='parametric curve')

# set the axis limits
ax.set_ylim(75,95)

# add axis labels
ax.set_xlabel('charge cycles to failure point of 75% capacity')
ax.set_ylabel('capacity at 100 charge cycles')
ax.set_zlabel('probability')`