Indicators in JavaScript
How to make a D3.js-based gauge chart in javascript.
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In this tutorial we introduce a new trace named "Indicator". The purpose of "indicator" is to visualize a single value specified by the "value" attribute. Three distinct visual elements are available to represent that value: number, delta and gauge. Any combination of them can be specified via the "mode" attribute. Top-level attributes are:
- value: the value to visualize
- mode: which visual elements to draw
- align: how to align number and delta (left, center, right)
- domain: the extent of the figure
Then we can configure the 3 different visual elements via their respective container:
- number is simply a representation of the number in text. It has attributes:
- valueformat: to format the number
- prefix: a string before the number
- suffix: a string after the number
- font.(family|size): to control the font
- reference: the number to compare the value with
- relative: whether that difference is absolute or relative
- valueformat: to format the delta
- (increasing|decreasing).color: color to be used for positive or decreasing delta
- (increasing|decreasing).symbol: symbol displayed on the left of the delta
- font.(family|size): to control the font
- position: position relative to
number
(either top, left, bottom, right)
title
with 'text' attribute which is a string, and 'align' which can be set to left, center, and right.
There are two gauge types: angular and bullet. Here is a combination of both shapes (angular, bullet), and different modes (guage, delta, and value):
var data = [
{
type: "indicator",
value: 200,
delta: { reference: 160 },
gauge: { axis: { visible: false, range: [0, 250] } },
domain: { row: 0, column: 0 }
},
{
type: "indicator",
value: 120,
gauge: {
shape: "bullet",
axis: {
visible: false,
range: [-200, 200]
}
},
domain: { x: [0.1, 0.5], y: [0.15, 0.35] }
},
{
type: "indicator",
mode: "number+delta",
value: 300,
domain: { row: 0, column: 1 }
},
{ type: "indicator", mode: "delta", value: 40, domain: { row: 1, column: 1 } }
];
var layout = {
width: 600,
height: 400,
margin: { t: 25, b: 25, l: 25, r: 25 },
grid: { rows: 2, columns: 2, pattern: "independent" },
template: {
data: {
indicator: [
{
title: { text: "Speed" },
mode: "number+delta+gauge",
delta: { reference: 90 }
}
]
}
}
};
Plotly.newPlot('myDiv', data, layout);
var data = [
{
domain: { x: [0, 1], y: [0, 1] },
value: 450,
title: { text: "Speed" },
type: "indicator",
mode: "gauge+number",
delta: { reference: 400 },
gauge: { axis: { range: [null, 500] } }
}
];
var layout = { width: 600, height: 400 };
Plotly.newPlot('myDiv', data, layout);
The equivalent of above "angular gauge":
var data = [
{
type: "indicator",
mode: "number+gauge+delta",
gauge: { shape: "bullet" },
delta: { reference: 300 },
value: 220,
domain: { x: [0, 1], y: [0, 1] },
title: { text: "Profit" }
}
];
var layout = { width: 600, height: 250 };
Plotly.newPlot('myDiv', data, layout);
Another interesting feature is that indicator trace sits above the other traces (even the 3d ones). This way, it can be easily used as an overlay as demonstrated below:
var data = [
{
type: "indicator",
mode: "number+delta",
value: 492,
delta: { reference: 512, valueformat: ".0f" },
domain: { y: [0, 1], x: [0.25, 0.75] },
title: { text: "Users online" }
},
{
y: [325, 324, 405, 400, 424, 404, 417, 432, 419, 394, 410, 426, 413, 419, 404, 408, 401, 377, 368, 361, 356, 359, 375, 397, 394, 418, 437, 450, 430, 442, 424, 443, 420, 418, 423, 423, 426, 440, 437, 436, 447, 460, 478, 472, 450, 456, 436, 418, 429, 412, 429, 442, 464, 447, 434, 457, 474, 480, 499, 497, 480, 502, 512, 492]
}
];
var layout = { width: 600, height: 450, xaxis: { range: [0, 62] } };
Plotly.newPlot('myDiv', data, layout);
Data card helps to display more contextual information about the data. Sometimes one number is all you want to see in a report, such as total sales, annual revenue, etc. This example shows how to visualize these big numbers:
var data = [
{
type: "indicator",
mode: "number+delta",
value: 400,
number: { prefix: "$" },
delta: { position: "top", reference: 320 },
domain: { x: [0, 1], y: [0, 1] }
}
];
var layout = {
paper_bgcolor: "lightgray",
width: 600,
height: 200,
margin: { t: 0, b: 0, l: 0, r: 0 }
};
Plotly.newPlot('myDiv', data, layout);
It's possible to display several numbers
var data = [
{
type: "indicator",
mode: "number+delta",
value: 200,
domain: { x: [0, 0.5], y: [0, 0.5] },
delta: { reference: 400, relative: true, position: "top" }
},
{
type: "indicator",
mode: "number+delta",
value: 350,
delta: { reference: 400, relative: true },
domain: { x: [0, 0.5], y: [0.5, 1] }
},
{
type: "indicator",
mode: "number+delta",
value: 450,
title: {
text:
"Accounts<br><span style='font-size:0.8em;color:gray'>Subtitle</span><br><span style='font-size:0.8em;color:gray'>Subsubtitle</span>"
},
delta: { reference: 400, relative: true },
domain: { x: [0.6, 1], y: [0, 1] }
}
];
var layout = {
width: 600,
height: 400,
margin: { t: 25, r: 25, l: 25, b: 25 }
};
Plotly.newPlot('myDiv', data, layout);