I am recently learning python, and I came across a package called scikit learn where we can use python libraries and custom made codes to generate various plots. I am already have installed all the dependancies and then I have downloaded and installed the scikit learn but when I am trying to run the example codes I am getting the error in generating the plot.
code
from sklearn import datasets
from sklearn.cross_validation import cross_val_predict
from sklearn import linear_model
import matplotlib.pyplot as plt
lr = linear_model.LinearRegression()
boston = datasets.load_boston()
y = boston.target
# cross_val_predict returns an array of the same size as `y` where each entry
# is a prediction obtained by cross validated:
predicted = cross_val_predict(lr, boston.data, y, cv=10)
fig,ax = plt.subplots() ## error comes from calling the function plt.subplots()
ax.scatter(y, predicted)
ax.plot([y.min(), y.max()], [y.min(), y.max()], 'k--', lw=4)
ax.set_xlabel('Measured')
ax.set_ylabel('Predicted')
fig.show()
Error
fig,ax = plt.subplots()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/pymodules/python2.7/matplotlib/pyplot.py", line 866, in subplots
fig = figure(**fig_kw)
File "/usr/lib/pymodules/python2.7/matplotlib/pyplot.py", line 343, in figure
**kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_tkagg.py", line 80, in new_figure_manager
window = Tk.Tk()
File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1712, in __init__
self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
_tkinter.TclError: no display name and no $DISPLAY environment variable
Is this something to do with setting up the environmental variable? I am using python 2.7.3 and this package should work with it or doing I have to put the path or something? sorry am very new to python just quickly trying to figure out if I can use this package for generating plots quickly or not. Any help to get rid of this error is appreciated.
I suspect that you are trying to run your code on a distant machine (
ssh
maybe) or simplymatplotlib
is not well installed.If you are in the first case, I would suggest to use
savefig
with the commandmatplotlib.use('Agg')
that tellsmatplotlib
to not use the default display. This will produce a.png
file that you could import it to your home usingscp
: