"Faceted" Tip marks

[ClockworkJustin]

Been running into an odd issue that I may be thinking about the wrong way, but I'm trying to create a reusable "scanner" that be used in some client charts to do something like this:

I have all the data in a single array with an X/Y value, but I want to basically have a ruleX using the pointerX transform to draw a line on the X axis that follows the mouse (which works great) but then I tried setting up like:

Plot.tip(
  allValues,
  Plot.pointerX({
    x: 'timeStamp',
    y: 'value',
    tip: true,
  })
),

And I want it to pull in all the Y values that match the X pointerX value but then "facet" them by like a type property but that didn't work. Like I wish I could do:

Plot.tip(
  allValues,
  Plot.pointerX({
    x: 'timeStamp',
    v: 'value',
    tip: {
      z: 'type',
    },
  })
),

which would then match on the X axis and pull all the Y values into the tooltip but then group the rendered values in the tip by using the type property.

Is this even possible? Can the Tip mark even accomplish what I want or will I need to do this with low level d3 stuff?
Thanks in advance for any tips/tricks/solutions! Trying not to invent a wheel if it already exists.

[Fil]

One way to retrieve all the values for a given x is to group on x, but I'm not sure that's what you want here? Can you share a notebook with some data and your current code? thanks

[ClockworkJustin]

Something like this: https://observablehq.com/d/e37999feb36b3c82

But I want the tip to show ALL the Y values in the one tip box. The reason being this chart could have 20+ lines all plotted and they can overlap and it becomes really hard to hover over a single line, so the idea was to instead just track the mouse over the X axis and then pull all Y values into a single tip. But currently the tip only shows the one matching X/Y that's closest to the mouse.

Here's what it looks like:

Here's what I want (new text in green):

Sorry if I'm not describing it well, it's hard to describe.

Thanks for the suggestion about group; I'll take a quick look at that.

[Fil]

You can use Plot.groupX if the timestamps are exactly the same; otherwise consider Plot.binX, with a lot of thresholds.

[Fil]

Here's a fancy implementation of the idea
https://observablehq.com/@observablehq/plot-grouped-tips

[ClockworkJustin]

This was EXACTLY what I was wanting! I didn't even know you could have the custom render function for an existing mark. That's incredible. A plot within a plot; never would have thought of that.