# Can't display tooltip at all in Vega Pie Chart
**URL:** https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056
**Category:** Kibana
**Tags:** vega
**Created:** [February 11, 2021, 9:21pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056 "2021-02-11T21:21:40Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Webtrend\_Inc](https://discuss.elastic.co/u/Webtrend_Inc)
#### Post date: [February 11, 2021, 9:21pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/1 "2021-02-11T21:21:41Z")
My following vega code correctly displays the actual chart and legend. However, I have been trying to get tooltip to display some data but the tooltips are not showing at all. Here is my latest code
```auto
{
"$schema": "https://vega.github.io/schema/vega/v4.0.json",
"title": "Top 10 IP Addresses",
"data": [
{
"name": "table",
"url": {
"%context%": "true",
"%timefield%": "@timestamp",
"index": "alb-logs-*",
"body": {
"aggs": {
"TopIP": {
"terms": {
"field": "elb_client_ip"
}
}
}
},
"size": 0
},
"format": {
"property": "aggregations.TopIP.buckets",
"as": "values"
},
"transform": [
{
"type": "pie",
"field": "doc_count"
}
]
}
],
"legends": [
{
"orient": "top-right",
"stroke": "color",
"title": "Origin",
"encode": {
"symbols": {
"update": {
"fill": {"value": ""},
"strokeWidth": {"value": 2},
"size": {"value": 64}
}
}
}
}
],
"scales": [
{
"name": "color",
"type": "ordinal",
"domain": {
"data": "table",
"field": "key"
},
"range": {
"scheme": "category20"
}
}
],
"marks": [
{
"type": "arc",
"from": {
"data": "table"
},
"encode": {
"enter": {
"fill": {
"scale": "color",
"field": "key"
},
"startAngle": {
"field": "startAngle"
},
"endAngle": {
"field": "endAngle"
},
"x": {
"signal": "width / 2"
},
"y": {
"signal": "height / 2"
},
"outerRadius": {
"signal": "min(width,height)/2.2"
},
"tooltip": {"signal": "datum.datum"}
}
}
}
]
}
```
What am I missing?
---
### Author:  [@wylie](https://discuss.elastic.co/u/wylie)
#### Post date: [February 11, 2021, 9:33pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/2 "2021-02-11T21:33:01Z")
Since you haven't provided a [reproduceable data set](https://www.elastic.co/guide/en/kibana/current/vega.html#asking-for-help-with-a-vega-spec) for us to try, it might be that we are going to miss something obvious as well.
That being said, what is the signal `datum.datum`? The value `datum` is bound to the current context of the signal, and you're binding it on `enter`. Maybe you need to fix both your signal reference and the phase of your binding.
> **[Marks](https://vega.github.io/vega/docs/marks/)**
>
> Vega - A Visualization Grammar. Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs. With Vega, you can describe the visual appearance and interactive behavior of a visualization...
> **[Expressions](https://vega.github.io/vega/docs/expressions/)**
>
> Vega - A Visualization Grammar. Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs. With Vega, you can describe the visual appearance and interactive behavior of a visualization...
---
### Author:  [@Webtrend\_Inc](https://discuss.elastic.co/u/Webtrend_Inc)
#### Post date: [February 12, 2021, 12:55am UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/3 "2021-02-12T00:55:01Z")
@wylie Thanks for your suggestions. I sorted out the issue. I was using wrong field name in tooltip section and as a result the tooltip was not visible.
One additional question: How do I show percentage value of each slice in the tooltip? I presume it requires some kind of mathematical transform to compute based on the total number of docs for a given aggregate bucket but my Vega grammar knowledge is extremely poor and I am struggling. Is there an example of this anywhere?
---
### Author:  [@wylie](https://discuss.elastic.co/u/wylie)
#### Post date: [February 12, 2021, 5:20pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/4 "2021-02-12T17:20:14Z")
I've never seen an example, but isn't that something you can calculated based on the `pie` transform? You could probably take `(datum.endAngle - datum.startAngle) / (2 * PI)` as your percentae.
---
### Author:  [@Webtrend\_Inc](https://discuss.elastic.co/u/Webtrend_Inc)
#### Post date: [February 13, 2021, 3:42am UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/5 "2021-02-13T03:42:05Z")
Excellent solution. I ended up with an expression like this
`"tooltip": {"signal": "'IP: '+ datum['key']+', Count: '+ datum['doc_count'] + ' Share: '+ ceil(((datum['endAngle']-datum['startAngle'])/(2*PI))*100) + '%'"}`
---
### Author:  [@wylie](https://discuss.elastic.co/u/wylie)
#### Post date: [February 13, 2021, 6:44pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/6 "2021-02-13T18:44:11Z")
You could also use the `format` function to do something like `format(value, '.2%')` if I remember the syntax correctly. It's using d3-format internally.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [March 13, 2021, 6:45pm UTC](https://discuss.elastic.co/t/cant-display-tooltip-at-all-in-vega-pie-chart/264056/7 "2021-03-13T18:45:09Z")
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