Bug report

Bug summary

When a scatter plot is made with data that contains np.nan (NaN), and then a color array is given usingset_color, the wrong colors get mapped to the data points.

Code for reproduction

frommatplotlibimportpyplotfrommatplotlib.colorsimportNormalizefrommatplotlibimportcmimportnumpyasnpx=np.linspace(0.0,1.0,50)y=np.linspace(0.0,1.0,50)norm=Normalize(0.0,1.0)colormap=cm.ScalarMappable(norm,'gnuplot')colors=colormap.to_rgba(y)# Expected colors with when x and y do not contain any np.nan.# Success.plot=pyplot.scatter(x,y,color=colors)pyplot.show()# Add some nan values.# If the color array is given during the initial creation of the# scatter plot, then everything works as expected.# Success.x[10:40]=np.nanplot=pyplot.scatter(x,y,color=colors)pyplot.show()# Again add some nan values.# If the color array is given as a call to set_color# then the colors no longer match the data.# Failure.x[10:40]=np.nanplot=pyplot.scatter(x,y)plot.set_color(colors)pyplot.show()

Actual outcome

Top: Expected colors with when x and y do not contain any np.nan.

Middle: Add some nan values. If the color array is given during the initial creation of the scatter plot, then everything works as expected.

Bottom: Again add some nan values. If the color array is given as a call toset_color then the colors no longer match the data.

Expected outcome

The colors corresponding to the data points should be displayed, even when data points contain NaN andset_color is used.

Matplotlib version

• Operating system: OSX
• Matplotlib version: 2.0.2
• Matplotlib backend: module://ipykernel.pylab.backend_inline & MacOSX
• Python version: 3.6.3
• Jupyter Notebook version: 5.2.0
• Other libraries: None