Set the `xbingroup` and `ybingroup` default prefix For example, setting a `bingroup` of *1* on two histogram2d traces will make them their x-bins and y-bins match separately.

Set a group of histogram traces which will have compatible x-bin settings. Using `xbingroup`, histogram2d and histogram2dcontour traces  (on axes of the same axis type) can have compatible x-bin settings. Note that the same `xbingroup` value can be used to set (1D) histogram `bingroup`

Set a group of histogram traces which will have compatible y-bin settings. Using `ybingroup`, histogram2d and histogram2dcontour traces  (on axes of the same axis type) can have compatible y-bin settings. Note that the same `ybingroup` value can be used to set (1D) histogram `bingroup`

Template string used for rendering the information that appear on hover box. Note that this will override `hoverinfo`. Variables are inserted using %{variable}, for example "y: %{y}". Numbers are formatted using d3-format's syntax %{variable:d3-format}, for example "Price: %{y:$.2f}". https://github.com/d3/d3-3.x-api-reference/blob/master/Formatting.md#d3_format for details on the formatting syntax. Dates are formatted using d3-time-format's syntax %{variable|d3-time-format}, for example "Day: %{2019-01-01|%A}". https://github.com/d3/d3-time-format#locale_format for details on the date formatting syntax. The variables available in `hovertemplate` are the ones emitted as event data described at this link https://plotly.com/javascript/plotlyjs-events/#event-data. Additionally, every attributes that can be specified per-point (the ones that are `arrayOk: true`) are available. variable `z` Anything contained in tag `<extra>` is displayed in the secondary box, for example "<extra>{fullData.name}</extra>". To hide the secondary box completely, use an empty tag `<extra></extra>`.

The sample data from which statistics are computed is set in `x` and `y` (where `x` and `y` represent marginal distributions, binning is set in `xbins` and `ybins` in this case) or `z` (where `z` represent the 2D distribution and binning set, binning is set by `x` and `y` in this case). The resulting distribution is visualized as a contour plot.