Plot.boxY is not a mark but four of them — a rule for the whiskers, a
bar for the interquartile box, a tick for the median, and a dot for the
outliers — and nothing in the DOM says they belong together. Read
individually they are worse than unreadable: the bar is a perfectly
ordinary bar mark whose height is q3 - q1, so a reader is told a number
that appears nowhere in the data and never hears the median or the whiskers
at all.
Two things identify it, and neither would do alone. How the parts sit on one
another narrows the field: every median lies inside its box and every whisker
runs along it, which an error bar chart and a bar chart with a target line do
not satisfy. And the median's own stroke width says which of the charts that
also satisfy it this is — a bullet chart and a candlestick with a marker in
its body arrange their parts exactly as a box plot does, because a floating
rect inside a rule with a line across it simply is that shape (#1088).
Because the second answers what the arrangement cannot, the first is only as
strict as every box plot really is: a whisker has to run along its box rather
than around it. Outliers move a quartile, and enough of them on one side pull it
past the whisker's end, so a perfectly ordinary box plot can have its box
stick out.
This is the outer gate. A composite it refuses is four marks that were never
a box plot, and is left to be read as whatever they are; one it finds but the
reader cannot pair up is skipped as it was before any of this was read
(#1074).
Finds the mark groups that make up a box plot.
Plot.boxYis not a mark but four of them — arulefor the whiskers, abarfor the interquartile box, atickfor the median, and adotfor the outliers — and nothing in the DOM says they belong together. Read individually they are worse than unreadable: thebaris a perfectly ordinary bar mark whose height isq3 - q1, so a reader is told a number that appears nowhere in the data and never hears the median or the whiskers at all.Two things identify it, and neither would do alone. How the parts sit on one another narrows the field: every median lies inside its box and every whisker runs along it, which an error bar chart and a bar chart with a target line do not satisfy. And the median's own stroke width says which of the charts that also satisfy it this is — a bullet chart and a candlestick with a marker in its body arrange their parts exactly as a box plot does, because a floating rect inside a rule with a line across it simply is that shape (#1088).
Because the second answers what the arrangement cannot, the first is only as strict as every box plot really is: a whisker has to run along its box rather than around it. Outliers move a quartile, and enough of them on one side pull it past the whisker's end, so a perfectly ordinary box plot can have its box stick out.
This is the outer gate. A composite it refuses is four marks that were never a box plot, and is left to be read as whatever they are; one it finds but the reader cannot pair up is skipped as it was before any of this was read (#1074).