Maps

Choropleth maps

Achoropleth mapis a color-coded map that assigns values as a function of location. Typically, the map is drawn along well-known political/administrative boundaries; hence, you don't have to create the maps yourself. A sliding scale of color helps you to quickly locate hot spots, where the value of interest may be lower or higher than other places on the map.

To create a choropleth map for your data, you need two things:

1. Map data. Via itsHighchartsback end, RapidMiner provides:

   • a world map, partitioned into countries,
   • maps of each continent, partitioned into countries, and
   • country maps, partitioned into lower-level administrative units (US States/German Länder/French Régions).

2. Anidentifier(e.g. a country name) that connects your data to the map. In principle, the ISO-3166 standard permits alpha or numeric codes as identifiers; in practice, RapidMiner uses the country name or name of the lower-level administrative unit.

Read more:

• Choropleth Maps (axismaps.com)
• Choropleth map (wikipedia)
• ISO 3166-1 (wikipedia)
• ISO 3166-2 (wikipedia)
• ISO 3166 country codes (iso.org)

Highcharts GeoJSON

Map data

The map data provided by RapidMiner began its life on theNatural Earthwebsite, and was converted to GeoJSON format byHighcharts.

GeoJSON is a special JSON format that describes shapes (such as the boundaries of a country) and associates properties to those shapes (such as name and ISO-3166 codes). For example, the GeoJSONFeaturethat describes the United States of America has the following form:

{
"type":"Feature",
"id":"US",
"properties":{
"hc-group":"admin0",
"hc-middle-x":0.68,
"hc-middle-y":0.68,
"hc-key":"us",
"hc-a2":"US",
"name":"United States of America",
"labelrank":"2",
"country-abbrev":"U.S.A.",
"subregion":"Northern America",
“region-wb”:"North America",
"iso-a3":"USA",
"iso-a2":"US",
"woe-id":"23424977",
"continent":"North America"
},
"geometry":{
"type":"MultiPolygon",
"coordinates":[
[
[
[
261,
8307
],
[
etc.
],
[
308,
8292
]
]
]
]
}
},

Identifier

An important point to observe is that the country name in the Highcharts GeoJSON file is not necessarily the same as theEnglish short namegiven by ISO-3166. To use the maps provided by RapidMiner / Highcharts, you must use thenamegiven in the Highcharts GeoJSON file.

For a complete list of ISO-3166 country names and codes, together with their Highcharts equivalents, see theappendix.

Note however that you can infer the Highcharts GeoJSON country name without ever opening a GeoJSON file, simply by:

• creating the map in RapidMiner and
• hovering the country with the mouse, until the country name appears.

Read more:

• Natural Earth
• The GeoJSON Format
• Highcharts - Map Collection

Example: Gapminder

Gapminder is an independent educational non-profit fighting global misconceptions.

The Gapminder Foundation collects and disseminates information about living standards in all parts of the world, to demonstrate how quickly and remarkably the global standard of living has increased, and to promote sustainable development.

TheGapminder websiteincludes a variety of global data.

GDP per capita in constant PPP dollars

For our example, we will plot the increase in GDP per capita in constant PPP dollars, from the year 2000 to the year 2020, using a modified version of aGapminder data set.

The following modifications:

• 删除GDP per capita growth (%).
• Restrict thetimedata to the years 2000 and 2020.
• Based on the year, rewriteIncome per personasIncome 2000andIncome 2020. Deletetime.
• Take the ratioIncome ratio=Income 2020/Income 2000.
• Take the natural log:Log ratio= ln (Income ratio)
• Rewrite countrynameasHighcharts name.

produce a table of this form:

Download gapminder-20-years.rmhdf5table

创建一个地图

Note that an app lives within a project. We havecreated a projectcalledgapminder. To create a map based on the above data table, take the following steps.

1. From within the project, under theData tab, clickAdd Data,uploadgapminder-20-years.rmhdf5table.
2. 从Content tab, selectCreate Appand name the appgapminder-progress.
3. ClickAdd Widget,Editthe widget.
4. In the dropdown, select the widget typeData.
5. In the Data Set dropdown, selectgapminder-20-years.
6. Visualize the data as aMap.

To configure the map, make the following selections:

• Map Type: Regions
• Map: All countries
• Regions:name, the country name given by Gapminder
• Value:Income ratio, the ratio betweenIncome 2020andIncome 2000
• Aggregation: No Aggregation

The resulting map has at least two flaws that can be corrected:

• The data for some countries, such as the United States and a few African countries, are not displayed on the map.
• Since most countries have anIncome ratioapproximately equal to 1.0, the map is drowning in a sea of purple.

Improve the map

Correct identifiers

Regarding the missing countries, the issue can be resolved by taking note of the comment onidentifiersmade previously: the country name must be the same as the name in the Highcharts GeoJSON file.

The data columnHighcharts namemakes the appropriate corrections.

Improve color coding

Regarding the color coding, theHighcharts API for colorAxishas some useful comments:

Often times, the color axis needs to be adjusted to get the right color spread for the data. In addition to stops, consider using a logarithmic axis type, or settingminandmax为了避免颜色being determined by outliers.

With this comment in mind, and taking into account theHighcharts name, we reconfigure the map, make the following selections:

• Map Type: Regions
• Map: All countries
• Regions:Highcharts name, the country name given by Highcharts
• Value:Log ratio, the natural logarithm ofIncome ratio
• Aggregation: No Aggregation

On this second map, the hot spots stand out more clearly.

• The countries where the economy has contracted are purple: Venezuela, Libya, South Sudan, Syria, and Yemen. Most of these countries have experienced armed conflict.
• The countries where the economy has expanded are yellow or orange. China stands out especially, but there has been dramatic progress in most of Asia and also in Eastern Europe.

Advanced settings

When you edit a map, clicking the buttonAdvanced Settingsgives you access to theHighcharts API. For maps, possible settings of interest include:

• title
• colorAxis

To change the configuration of thetitle, for example, enter a JSON snippet similar to the following into the form field:

{
"title":{
"text":"Log[ (Income 2020) / (Income 2000) ]",
"align":"left",
"x":90,
"y":60,
"style":{
"color":"#772222"
}
}
}

Read more:

• Gapminder
• Gapminder data
• GDP per capita in constant PPP dollars
• Ted Talk by Hans Rosling: The best stats you've ever seen
• Highcharts API
• Highcharts API for colorAxis

Appendix: conversion table

The table below presents the ISO-3166-1 standard for country codes, and shows eventual differences between theEnglish short nameidentified in ISO-3166-1 and the country names identified by Highcharts. To get your data on the map, you need to use theHighcharts name.

Download the conversion table