"min() arg è una sequenza vuota" quando si tenta di convertire il mio diagramma di panda in plot

Question

Ricevo un ValueError: min() arg is an empty sequence quando provo a convertire un grafico di panda dati su trama.

Ecco un esempio del dataframe (con NaNs):

ttab.loc[:,:"Irish"]

Group English (British) Americans (White) Canadians Scots Irish 
Year      
1926 1 2 3 4 5 
1946 3 1 2 5 4 
1956 3 1 2 7 5 
1966 2 1 3 9 5 
1977 2 1 3 9 7 
1993 2 NaN NaN 6 1 
2001 4 1 3 NaN 5 
2001* 4 1 3 NaN 5 
2012 4 1 3 NaN 6 

Faccio una bella trama:

# Time It 
import time 
begin = time.clock() 

# Inline plotting 
%matplotlib inline 

# Import libraries 
import matplotlib 
import numpy as np 
import matplotlib.pyplot as plt 
import pandas as pd 
import seaborn as sns 
from pandas.tools.plotting import scatter_matrix 

# (*) To communicate with Plotly's server, sign in with credentials file 
import plotly.plotly as py 
# (*) Useful Python/Plotly tools 
import plotly.tools as tls 
# (*) Graph objects to piece together plots 
from plotly.graph_objs import * 

# Read, clean, slice data here... 
# Rename columns, examine, rename groups here... 
# Merge, set index, transpose dataframe here.... 
# Change datatype to float here... 
# Define color palette here... 
# Now Plot... 

# Package all mpl plotting commands inside one function 
def plot_mpl_fig(): 

    # plot parameters 
    figsize = (12,12) 
    axfontsize = 16 
    legfontsize = 14 
    labfontsize = 18 
    yax = (30,0) 
    lw = 2 

    # Interpolate NaNs and plot as dashed lines 
    ax = ttab.loc[:,:'Asian Indians'].interpolate().plot(color=colorlist, ylim=yax, lw=lw, fontsize=axfontsize, \ 
                figsize=figsize, style='--') 

    # Overplot the measured values with solid lines 
    ttab.loc[:,:'Asian Indians'].plot(ax=ax, color=colorlist, ylim=yax, lw=lw, fontsize=axfontsize, figsize=figsize) 

    # Legend handling 
    lines, labels = ax.get_legend_handles_labels() 
    ax.legend(lines[28:], labels[28:], loc='center left', bbox_to_anchor=(-0.3, 0.5), fontsize=legfontsize) 

    # Labeling 
    plt.xlabel('Year',fontsize=labfontsize) 
    plt.ylabel('Rank',fontsize=labfontsize) 

# Plot it! 
plot_mpl_fig() 

# N.B. get matplotlib figure object and assign a variable to it 
mpl_fig1 = plt.figure() 

E poi cerco di convertire seguendo la esempio: https://plot.ly/python/matplotlib-to-plotly-tutorial/

Avvio rapido:

>>> import plotly.plotly as py 
>>> import matplotlib.pyplot as plt 
>>> # auto sign-in with credentials or use py.sign_in() 
>>> mpl_fig_obj= plt.figure() 
>>> # ... make a matplotlib figure ... 
>>> py.plot_mpl(mpl_fig1)         # <== ValueError 

o tutorial alla Sezione 6.1:

# Convert a matplotlib figure object to a Plotly figure object 
help(tls.mpl_to_plotly) 
py_fig1 = tls.mpl_to_plotly(mpl_fig1, verbose=True)   # <== ValueError 
print(py_fig1.to_string()) 
# Plot a matplotlib figure in Plotly 
help(py.iplot_mpl) 
py.iplot_mpl(mpl_fig1, filename='s6_damped_oscillation') # <== ValueError 

Ogni volta che io chiamo plot_mpl, mpl_to_plotly, o iplot_mpl ho la ValueError: min() arg is an empty sequence. Penso che potrebbe avere a che fare con i NaN, ma non so come aggirarli. Eventuali suggerimenti?

Answer 1

Sembra che mpl_to_plotly richieda l'utilizzo di axes.plot(), non di plt.plot(). Il seguente codice funziona in un taccuino Jupyter.

import plotly.offline as py 
from plotly.offline import init_notebook_mode, iplot 
import plotly.tools as tls 
import matplotlib.pylab as plt 
from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas 

init_notebook_mode(connected=True) 
fig = plt.Figure() 
ax = fig.gca() 
x = [-2,0,4,6,7] 
y = [q**2-q+3 for q in x] 
ax.plot(x,y) 
canvas = FigureCanvas(fig) 
plotly_fig = tls.mpl_to_plotly(fig) 
py.iplot(plotly_fig)