Plotting shaded uncertainty region in line plot in matplotlib when data has NaNs

Question

I would like a plot which looks like this:

I am trying to do this with matplotlib:

fig, ax = plt.subplots()

with sns.axes_style(\"darkgrid\"):
             


        

Answer 1

You could simply drop the NaNs from your means DataFrame and plot that resulting dataframe instead?

In the example below, I tried to get close to your structure, I have a means DataFrame with some NaN sprinkled around. I suppose the stds DataFrame probably has NaN at the same locations, but in this case it doesn't really matter, I drop the NaN from means to get temp_means and I use the indices left in temp_means to extract the std values from stds.

The plots show the results before (top) and after (bottom) dropping the NaNs

x = np.linspace(0, 30, 100)
y = np.sin(x/6*np.pi)
error = 0.2

means = pd.DataFrame(np.array([x,y]).T,columns=['time','mean'])
stds = pd.DataFrame(np.zeros(y.shape)+error)

#sprinkle some NaN in the mean
sprinkles = means.sample(10).index
means.loc[sprinkles] = np.NaN


fig, axs = plt.subplots(2,1)

axs[0].plot(means.ix[:,0], means.ix[:,1])
axs[0].fill_between(means.ix[:,0], means.ix[:,1]-stds.ix[:,0], means.ix[:,1]+stds.ix[:,0])

temp_means = means.dropna()

axs[1].plot(temp_means.ix[:,0], temp_means.ix[:,1])
axs[1].fill_between(temp_means.ix[:,0], temp_means.ix[:,1]-stds.loc[temp_means.index,0], temp_means.ix[:,1]+stds.loc[temp_means.index,0])


plt.show()