Bug report

Bug summary

The color bar has multiple labels with the value 0 ifmatplotlib.colors.SymLogNorm is used leading to a "bold-looking" label.

Code for reproduction

frommatplotlibimportpyplotaspltimportmatplotlibasmplfig,axes=plt.subplots(1,2,True,True)fori,axinenumerate(axes):im=ax.imshow([[0]],norm=mpl.colors.SymLogNorm(1e-5,vmin=-1,vmax=1))cb=plt.colorbar(im,ax=ax)# Clean up the labelszero_labelled=Falseforlabelincb.ax.yaxis.get_ticklabels():iflabel.get_text()==r'$\mathdefault{0}$':ifzero_labelled:label.set_visible(False)zero_labelled=True

Actual outcome on the left, expected outcome on the right

Matplotlib version

• Operating system: Linux 1061836d2c20 4.9.49-mobyFix autofmt_xdate() when using in conjunction with twinx() #1 SMP Fri Dec 8 13:40:02 UTC 2017 x86_64 GNU/Linux
• Matplotlib version: 2.1.1
• Matplotlib backend (print(matplotlib.get_backend())): module://ipykernel.pylab.backend_inline
• Python version: 3.6.3
• Jupyter version (if applicable): 4.4.0
• Other libraries: numpy (1.13.3)

All libraries were installed using pip in a docker image derived frompython:3.