# Categorical variables and twinx make basically no sense

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## Categorical variables and twinx make basically no sense

 Example code is pasted below. Basically, just wanted to say that this is either completely non-intuitive, or I am failing to understand something fundamental about matplotlib.My impression would be that twinx would let me assign categorical values to however they were before I twinned them (i.e., using the original axis' order and coordinates). But, if you use categorical values, it will truncate them to the length of the categorical list/array. In the example code, if you comment out the x1/x2 categorical assignments and use integers instead (uncomment those), it works as you'd expect. You can even swap the order in which the integers are plotted, but NOT if you use the text assignments, despite the fact that the integer and text axes are the same.Gallery: https://imgur.com/a/NTgCFXBAnyway, someone please let me know if there is some design principle I'm missing here, or if this is a special case. It's missing from any of the top level documentation (see: https://matplotlib.org/gallery/lines_bars_and_markers/categorical_variables.html , https://matplotlib.org/examples/api/two_scales.html ) and took me the better part of this afternoon to figure out. The only conclusion I can come to is that matplotlib treats these values differently, and converts the text arrays to integers under the hood without trying to align them.Cheers,AJCode:import matplotlib.pyplot as pltx1 = ['apples', 'bananas', 'cheerios']##x1 = [1,3,5]y1 = [5, 6, 15]x2 = ['apples','carrots','bananas','watermelon','cheerios']##x2 = [1,2,3,4,5]y2 = [100, 200, 300, 400, 500]fig, ax = plt.subplots()ax.scatter(x2, y2)ax2 = ax.twinx()ax2.scatter(x1, y1, color = "orange")plt.show() _______________________________________________ Matplotlib-users mailing list [hidden email] https://mail.python.org/mailman/listinfo/matplotlib-users