Mutivariate data visualization

Weather stations styled with a simple renderer and visual variables to display wind speed, direction, and air temperature

What is multivariate data visualization?

Multivariate variate data visualization involves visualizing more than one data value in a single renderer. This is done for many reasons, including to:

  1. View the relationship between two or more variables
  2. Compare or contrast the difference between two variables
  3. View spatial patterns that may not be related among several variables at one time.

How multivariate data visualizations work

Multivariate visualizations can be done by adding more than one visual variable to a simple renderer. Common combinations include:

  1. Color and size
  2. Size and rotation
  3. Size, rotation, and color

Examples

Color and size

Color and size are typically used to show the relationship between two variables or to show a rate with a color variable, and the magnitude of a variable using a size variable.

The following example visualizes how humidity influences the heat index, or the "feels like" temperature using color and size.

  • color is used to visualize relative humidity
  • size is used to visualize the difference between the heat index (feels like temperature) and the measured air temperature at a weather station.
ArcGIS JS API
                                                                                                                       
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <title>ArcGIS Developer Guide: Visual variables (size and color)</title>
    <style>
      html,
      body,
      #viewDiv {
        padding: 0;
        margin: 0;
        height: 100%;
        width: 100%;
    </style>

    <link rel="stylesheet" href="https://js.arcgis.com/4.21//esri/themes/light/main.css" />
    <script src="https://js.arcgis.com/4.21//"></script>

    <script>
      require([
        "esri/config",
        "esri/Map",
        "esri/views/MapView",
        "esri/layers/FeatureLayer",
        "esri/widgets/Legend",
        "esri/widgets/Expand"
      ],(
        Map,
      )=> {
        esriConfig.apiKey = "YOUR_API_KEY";
        const renderer = {
          type: "simple",
          symbol: {
            type: "simple-marker",
            style: "circle",
            color: [50, 50, 50],
            outline: {
              color: [255, 255, 255, 0.5],
              width: 0.5
            size: "8px"
          visualVariables: [
            {
              type: "size",
              valueExpression: "$feature.HEAT_INDEX - $feature.TEMP",
              valueExpressionTitle: "Difference in 'feels like' temperature from air temperature",
              minDataValue: 0,
              maxDataValue: 30,
              minSize: 4,
              maxSize: 24
            }, {
              type: "color",
              field: "R_HUMIDITY",
              stops: [
                { value: 20, color: "#ffefdc" },
                { value: 35, color: "#edac90" },
                { value: 50, color: "#da6843" },
                { value: 65, color: "#a03523" },
                { value: 80, color: "#660202" }
              ]
            }
          ]
        // Set the renderer on the feature layer
        const layer = new FeatureLayer({
          portalItem: {
            id: "cb1886ff0a9d4156ba4d2fadd7e8a139"
          title: "Current weather conditions",
          renderer: renderer
        const map = new Map({
          basemap: {
            portalItem: {
              id: "ba223f982a3c4a0ea8c9953346e2a201"
          layers: [layer]
        const view = new MapView({
          container: "viewDiv",
          map: map,
          scale: 36978595,
          center: [ -80.48, 28.30 ],
          constraints: {
            snapToZoom:false
        view.ui.add(new Expand({
          content: new Legend({
            view: view
          view: view,
          expanded: false
        }), "top-right");
    </script>
  </head>
  <body>
    <div id="viewDiv"></div>
  </body>
</html>

Size and rotation

Size variables are good for visualization total counts or magnitudes. Rotation and size are commonly paired together to map weather data, such as wind. Rotation indicates the direction of flow, while size indicates the wind speed.

ArcGIS JS API
                                                                                                                      
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <title>ArcGIS Developer Guide: Visual variables (size and rotation)</title>
    <style>
      html,
      body,
      #viewDiv {
        padding: 0;
        margin: 0;
        height: 100%;
        width: 100%;
    </style>

    <link rel="stylesheet" href="https://js.arcgis.com/4.21//esri/themes/light/main.css" />
    <script src="https://js.arcgis.com/4.21//"></script>

    <script>
      require([
        "esri/config",
        "esri/Map",
        "esri/views/MapView",
        "esri/layers/FeatureLayer",
        "esri/widgets/Legend",
        "esri/widgets/Expand"
      ],(
        Map,
      )=> {
        esriConfig.apiKey = "YOUR_API_KEY";
        const referenceScale = 9244650*2;
        const renderer = {
          type: "simple",
          symbol: {
            type: "simple-marker",
            // Arrow marker defined as SVG path
            path: "M14.5,29 23.5,0 14.5,9 5.5,0z",
            color: [50, 50, 50],
            outline: {
              color: [255, 255, 255, 0.5],
              width: 0.5
            angle: 180,
            size: "20px"
          visualVariables: [
            {
              type: "size",
              field: "WIND_SPEED",
              minDataValue: 5,
              maxDataValue: 60,
              minSize: 4,
              maxSize: 24
            }, {
              type: "rotation",
              field: "WIND_DIRECT",
              rotationType: "geographic"
            }
          ]
        // Set the renderer on the feature layer
        const layer = new FeatureLayer({
          portalItem: {
            id: "cb1886ff0a9d4156ba4d2fadd7e8a139"
          title: "Current weather conditions",
          renderer: renderer
        const map = new Map({
          basemap: {
            portalItem: {
              id: "ba223f982a3c4a0ea8c9953346e2a201"
          layers: [layer]
        const view = new MapView({
          container: "viewDiv",
          map: map,
          scale: referenceScale,
          center: [ -95, 38.5 ],
          constraints: {
            snapToZoom:false
        view.ui.add(new Expand({
          content: new Legend({
            view: view
          view: view,
          expanded: false
        }), "top-right");
    </script>
  </head>
  <body>
    <div id="viewDiv"></div>
  </body>
</html>

Size, rotation, and color

In rare cases, you can effectively use three visual variables together. In the example below, we add a color variable to the wind visualization to represent air temperature. This visualization allows the end user to view patterns of wind and temperature together in one visual.

  • Size - wind speed
  • Rotation - wind direction
  • Color - air temperature
ArcGIS JS API
                                                                                                                                                     
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <title>ArcGIS Developer Guide: Multiple visual variables</title>
    <style>
      html,
      body,
      #viewDiv {
        padding: 0;
        margin: 0;
        height: 100%;
        width: 100%;
    </style>

    <link rel="stylesheet" href="https://js.arcgis.com/4.21//esri/themes/light/main.css" />
    <script src="https://js.arcgis.com/4.21//"></script>

    <script>
      require([
        "esri/config",
        "esri/Map",
        "esri/views/MapView",
        "esri/layers/FeatureLayer",
        "esri/widgets/Legend",
        "esri/widgets/Expand"
      ],(
        Map,
      )=> {
        esriConfig.apiKey = "YOUR_API_KEY";
        const referenceScale = 9244650*2;
        const renderer = {
          type: "simple",
          symbol: {
            type: "simple-marker",
            // Arrow marker defined as SVG path
            path: "M14.5,29 23.5,0 14.5,9 5.5,0z",
            color: [250, 250, 250],
            outline: {
              color: [255, 255, 255, 0.5],
              width: 0.5
            angle: 180,
            size: 15
          visualVariables: [
            {
              type: "rotation",
              field: "WIND_DIRECT",
              rotationType: "geographic"
            },
            {
              type: "size",
              field: "WIND_SPEED",
              minDataValue: 5,
              maxDataValue: 60,
              minSize: {
                type: "size",
                valueExpression: "$view.scale",
                // adjust the min size by scale
                stops: [
                  { value: referenceScale, size: 8 },
                  { value: referenceScale*2, size: 6 },
                  { value: referenceScale*4, size: 4 },
                  { value: referenceScale*8, size: 2 }
                ]
              },
              maxSize: {
                type: "size",
                valueExpression: "$view.scale",
                // adjust the max size by scale
                stops: [
                  { value: referenceScale, size: 40 },
                  { value: referenceScale*2, size: 30 },
                  { value: referenceScale*4, size: 20 },
                  { value: referenceScale*8, size: 10 }
                ]
              }
            },
            {
              type: "color",
              field: "TEMP",
              stops: [
                { value: 20, color: "#2b83ba" },
                { value: 35, color: "#abdda4" },
                { value: 50, color: "#ffffbf" },
                { value: 65, color: "#fdae61" },
                { value: 80, color: "#d7191c" }
              ]
            }
          ]
        // Set the renderer on the feature layer
        const layer = new FeatureLayer({
          portalItem: {
            id: "cb1886ff0a9d4156ba4d2fadd7e8a139"
          title: "Current weather conditions",
          renderer: renderer
        const map = new Map({
          basemap: {
            portalItem: {
              id: "ba223f982a3c4a0ea8c9953346e2a201"
          layers: [layer]
        const view = new MapView({
          container: "viewDiv",
          map: map,
          scale: referenceScale,
          center: [ -95, 38.5 ],
          constraints: {
            snapToZoom: false
        view.ui.add(new Expand({
          content: new Legend({
            view: view
          view: view,
          expanded: false
        }), "top-right");
    </script>
  </head>
  <body>
    <div id="viewDiv"></div>
  </body>
</html>

Best practices

Keep in mind that using more than one visual variable adds complexity to the visualization. This makes it more difficult for the end user to understand the message. You should always carefully consider whether using multiple variables in one view is preferable to displaying separate views of the data.

Other multivariate styles

You don't need visual variables to create multivariate visualizations. The following guide pages demonstrate how to create multivariate visualizations with other renderer types.

Predominance

A predominance visualization colors features based on the predominant value among a set of competing or similar numeric attributes.

Dot density

Learn how to use dot density to measure the density of a numeric attribute or set of comparable variables.

Relationship

Learn how to use a relationship renderer to explore the relationship between two numeric data attributes.

Tutorials

Services

Feature service

Add, update, delete, and query feature data.

API support

Different APIs have different levels of support for data-driven visualization.

Full supportPartial supportNo support

    Tools

    Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.