How essential is it for C3 to sort the x axis list?

Plotting experience from Python/Matplotlib, R, Matlab, Excel, etc., suggests that the ordering of the x values of a plot is important, i.e., if you use a non-sorted list of for your x axis and ask for a line plot, you’ll get a jagged line. C3.js doesn’t do this: it’ll sort the x-axis data before drawing a “normal-looking” (but unexpected, and in some cases, incorrect) plot.

How important is this decision to C3’s design? Can it be relaxed by a user-settable parameter?

var chart = c3.generate({
    bindto : '#ch',
    data : {
        x : 'x',
        rows : [
            [ 'x', 'data1', 'data2' ],
            [ 11, 120, 300 ],
            [ 22, 160, 240 ],
            [ -33, 200, 290 ], // <----- note shuffled x point
            [ 44, 160, 230 ],
            [ 55, 130, 300 ],
        ]
    }
});

Background: I’m using tooltip.contents and a non-sorted list for x in a scatter plot, and have to create a lookup object to transform the x values to indexes just for this. The x list can’t be stored sorted because it indexes many other lists.

[masayuki0812]

Hi, Thank you for the feedback and the discussion. I added data.xSort option to determine whether the data will be sorted or not by x values.

Now you can do that by setting this option false, then the sort will be skipped and the order of the data will be maintained. Than, you can access the element of unsorted data by the index obtained from data in tooltip.content. Could you try the latest code? Thanks.

[OttoG]

@shafiquejamal it works for me with version 0.4.11. Setting <c3 chart object>.data.xSort = false solved a problem similar to the one described by the original poster. The dots keep their index numbers from the supplied data set (and the corresponding drawing order is respected) regardless of their x values.

That version is rather old, though. Perhaps the functionality has become broken in later versions?