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Most charting packages have a terrible default: set y axis original point around y min, which is rarely appropriate in data visualization. In my opinion, the de
by datashow 7y ago
Most charting packages have a terrible default: set y axis original point around y min, which is rarely appropriate in data visualization. In my opinion, the default should always be zero.
Another one is bars in bar/column charts are horribly wide.
- omginternets 7y agoAlso, the jet colormap.
- geoalchimista 7y ago> In my opinion, the default should always be zero. This won't work well for a lot of cases. Imagine plotting the atmospheric CO2 concentration time series in the past 200 years. Setting the original point at zero ppm would not make sense because it can never happen. I'd say setting y axis original point at y min is a good trade-off since the plotting package is agnostic about the underlying nature of the plot.
- datashow 7y agoI agree you may give a valid exception (I don't know the field), it may represent a large field. But I still think broadly speaking it is uncommon, but I don't have data to back it up.
- nemetroid 7y ago> Setting the original point at zero ppm would not make sense because it can never happen. Why does that matter? I disagree. A graph item representing the amount of stuff in some context should double in size (exactly) if the amount of stuff doubles.
- danso 7y agoI have mixed feelings. I agree that "y-axis should start at zero" should not be been as a sacred guideline by any means. But I reflexively feel that in the context of a data viz library, the default should be zero; thus requiring the user to explicitly set a minimum when needed, and to conscientiously do so. But I do realize that practically speaking, it is much easier to set a y-axis to 0 (i.e. a constant value), rather than having to calculate the y-min or near-y-min for every chart.
- mattkrause 7y agoHow would that work with negative data?
- datashow 7y agoWhat do you mean? Zero original point does not work with negative data?
- mattkrause 7y agoThe OP's suggestion was that the y-axis should start at zero by default, not min(y). However, this seems like it would lead to empty plots when the data is all or mostly negative.
- datashow 7y agoNot really. Plot can be shown above and below the x-axis.
- djrobstep 7y agoThis a common claim, but really non-zero y-mins are absolutely fine. Do you think that every weather chart is wrong because it doesn't begin from absolute zero? Usually when charts have misleading y-ranges, the real problem is lack of x-axis context. For instance, a chart with unemployment over the last three years can be made clearer by showing unemployment over the last 50 years. Much better to give a wider picture than pointlessly add whitespace.
- glofish 7y agozero y-mins are usually recommended to show both the absolute values and relative variation at the same time. Based on my own experience, the number of plots that are misleading because they do not start at zero is far greater than that of those that are insufficiently informative because they do start at zero. That alone is not a reason for "banning" non-zero ymins, but it is definitely a good reason to more critically evaluate their use.