Gauge

Each point draws as a ring filled to its value's share of a maximum, with the percentage or the value at its centre and the place's name under it. The ring can be swapped for a marker that fills: a thermometer, a tank, a battery, a drop or any icon from the catalogue.

See it in the layer tour

The Power grid map of the layer tour, installed with the app, draws each country's renewable share as a ring filled from 0 to 100, red below 30, amber below 60, green above, with the percentage in the middle. It reads synthetic data, so it draws with no setup; press ▶ on its time filter to play the day. Grafana may replace the dashboard when the app is updated, so copy it before customising it.

What the query needs

A position and one numeric column for the value:

SELECT site        AS name,
       lat         AS latitude,
       lon         AS longitude,
       utilisation
FROM site_status;

The position can also come from a place name instead of coordinates. For sites named by a label, use an instant PromQL query with Format set to Table:

avg by (site) (utilizacion_pct)

Places turns the label into place, latitude and longitude columns, and the value arrives in a column called Value. Places detects a label by its name, and site is not one of the names it recognises, so name it as the query's Column in the Places options. Its values then have to be places Places knows: cloud regions, airport or PoP codes, countries. Sites known only by names of your own need latitude and longitude columns in the query instead.

A Gauge layer is never created by itself. Add it in kepler's side panel with + Add Layer, choose Gauge as the type, and assign the latitude and longitude columns. Underneath, it is kepler's point layer, and these point settings carry over:

• Color Based On picks the value column. The fill level, the centre text and the colour all come from it.
• The colour range colours each gauge by that value. A custom scale sets breaks such as 70 and 90; see Colour palettes and scales. Grafana's thresholds do not apply.
• Radius sets the gauge's size in pixels.
• Text label writes a column, such as the place name, under the gauge.

Options

The Gauge group comes after the point layer's own settings. Some rows only appear when another setting needs them.

Option	What it does	Default
Shape	Ring, Thermometer, Tank, Battery, Drop or Icon	Ring
Icon	The catalogue icon that fills, when Shape is Icon	square
Position	Center, or Above, Right, Below or Left of the point	Center
Distance	Gap in pixels between the point and the gauge, 0 to 120; shown when Position is not Center	30
Over roads and labels	Keeps the gauges over the base map groups moved to the top (roads, labels) and over other layers	on
Per place	Which rows a place draws: All rows, Last, Min or Max	Last
Asset	The column that tells moving things apart: Auto, None (by position), or a column	Auto
History	What the popup charts: Off, Color field, or any numeric column	Color field
Minimum	The value an empty gauge stands for	0
Maximum	The value a full gauge stands for; leave it empty for auto	auto
Centre shows	Percentage of the range, or the Value itself	Percentage
Unit	Text appended to the value, exactly as typed; shown when Centre shows is Value	empty
Upright (3D)	Stands the ring up, facing the camera, when the map is tilted; Ring only	off
Centre text	Draws the percentage or value	on
Centre text colour	Colour of that text	follows the Grafana theme
Centre text size	In pixels, 8 to 40	18
Ring thickness	Width of the filled arc in pixels, 1 to 30; Ring only	4
Outline width	Outline of a Thermometer, Tank, Battery or Drop, 1 to 30	4
Shrink when zooming out	Makes the gauges smaller as the map zooms out	off
Full size from zoom	The zoom at and above which gauges keep their full size, 0 to 22; Use current zoom fills it in	10
Shrink rate	0 never shrinks, 1 halves the size per zoom level	0.5
Background disc	A disc behind the ring; Ring only	off
Background colour	Colour of that disc	dark blue-grey
Background opacity	0 to 1	0.6

Minimum and maximum

The gauge fills to (value − Minimum) / (Maximum − Minimum), held between empty and full. With the maximum on auto, it is 1 when every value is at most 1 and 100 otherwise, so a 0–1 ratio and a 0–100 percentage both read correctly without setting anything. A metric that can exceed 100, or that does not start at 0 like a temperature, needs both numbers set. A maximum at or below the minimum is ignored and read as auto.

Percentage prints the share of the range, rounded to a whole number. Value prints the reading itself, rounded to one decimal, even when it lies outside the range and the gauge is simply empty or full. Type the unit with any space you want before it: °C gives 23.4°C, kW gives 23.4 kW.

Shapes

The tank, the drop and an icon fill from the bottom up, the battery from left to right. The thermometer's bulb is full as soon as the value is above the minimum; its tube carries the reading. Markers always face the camera, so Upright (3D) applies to the ring only. With Centre text on, a marker writes its text below itself rather than inside, and the name label moves down to make room.

The icons are the same catalogue as the free panel's symbols.

Beside the point

With Position set to anything other than Center, the gauge moves Distance pixels away from its point and a thin leader line joins them. The gap is in screen pixels, so it looks the same at every zoom and tilt. Use it when another layer draws something at the same spot, such as a vehicle or a site icon, that the gauge would otherwise cover.

Behaviour worth knowing

• One gauge per place. A query that returns a time series per site would pile gauges on the same spot. Per place keeps one row for each: the newest (Last), or the one with the lowest or highest value (Min, Max). All rows draws every one. A place is its coordinates, or its Asset when the rows belong to something that moves; see Plus layers.
• Time filter. The gauges follow kepler's filters and the time filter: as it plays, each place shows its row in the window. An auto maximum is worked out from every row, not only the visible ones, so it does not jump while the time filter plays.
• Moving assets. With Per place on Last and an asset column, a gauge glides between the asset's reported positions as the time filter plays, keeping the value of its last report.
• Clicks and polygons. A click on a gauge reaches the panel's click variables (see Cross-filtering), and a polygon drawn with kepler's draw tool filters the gauges as it does kepler's own layers.
• Hover. The popup shows the row's fields and, under them, the place's history over the dashboard's range. Turning off kepler's Allow hover for the layer turns both off.

When it does not draw

• No layer at all. Unlike kepler's point layer, a Gauge layer is never added automatically. Add it by hand, or copy the layer tour's Power grid map.
• Empty gauges with no text. No Color Based On column is set, or its values are not numbers. A row whose value is empty or not a number draws an empty gauge.
• Every gauge full. The values are above the maximum: an auto maximum is 100 at most, so set Maximum for anything larger.
• Every gauge nearly empty. The values sit below Minimum, or a 0–1 ratio has one stray value above 1, which makes auto read 100.
• Sites named by a label do not draw. The query returns no series, or the site values are not places Places recognises: return latitude and longitude instead.
• Gauges missing in one area. A kepler filter, a drawn polygon or the time filter's window leaves those rows out.

Use it for

Site and data centre utilisation, storage and tank levels, battery charge across a fleet of devices, reservoir levels, temperatures at weather or cold-chain sites, renewable share per country.