# Paste your code here"""Hatching (pattern filled polygons) is supported currently in the PS,PDF, SVG and Agg backends only."""importmatplotlibmatplotlib.use('Agg')#the same happen also without this line backend TkAggimportmatplotlib.pyplotaspltfrommatplotlib.patchesimportEllipse,Polygonfig=plt.figure()ax1=fig.add_subplot(131)ax1.bar(range(1,5),range(1,5),color='red',edgecolor='black',hatch="/")ax1.bar(range(1,5), [6]*4,bottom=range(1,5),color='blue',edgecolor='black',hatch='//')ax1.set_xticks([1.5,2.5,3.5,4.5])ax2=fig.add_subplot(132)bars=ax2.bar(range(1,5),range(1,5),color='yellow',ecolor='black')+ \ax2.bar(range(1,5), [6]*4,bottom=range(1,5),color='green',ecolor='black')ax2.set_xticks([1.5,2.5,3.5,4.5])patterns= ('-','+','x','\\','*','o','O','.')forbar,patterninzip(bars,patterns):bar.set_hatch(pattern)ax3=fig.add_subplot(133)ax3.fill([1,3,3,1], [1,1,2,2],fill=False,hatch='\\')ax3.add_patch(Ellipse((4,1.5),4,0.5,fill=False,hatch='*'))ax3.add_patch(Polygon([[0,0], [4,1.1], [6,2.5], [2,1.4]],closed=True,fill=False,hatch='/'))ax3.set_xlim((0,6))ax3.set_ylim((0,2.5))#plt.show()plt.savefig('hatch_demo.pdf')plt.savefig('hatch_demo.png')plt.savefig('hatch_demo.eps')print(matplotlib.__version__)print(matplotlib.get_backend())