Explore the latest version of An Elementary Introduction to the Wolfram Language »
 16 Real‐World Data
Enter the plain English united states:
Press the check mark to confirm thats what you want:
Ask for the flag property of the United States:
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The result you get is something you can go on doing computation withlike in this case image processing.
Color-negate the US flag:
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If all you want to do is to get the US flag, you can just ask for it in English.
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EntityValue is a more flexible way to ask for the values of properties.
Use EntityValue to get the US flag:
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EntityValue also works with lists of entities.
Get flags for a list of countries:
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The Wolfram Language has deep knowledge about countries, as about many other things.
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Find their flags:
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Ask for planets, and get the class of entities corresponding to planets:
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Get the list of planets:
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EntityValue can actually handle entity classes directly, so you dont need to use EntityList with it.
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Show the internal form of the entity that represents the United States:
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There are millions of entities in the Wolfram Language, each with a definite internal form. In principle you could enter any entity using its internal form. But unless youre using the same entity over and over again, its much more practical just to use ctrl+= and enter a name for the entity in plain English.
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In practice, though, a good approach is to ask in plain English for a property of some entity, then to look at the interpretation thats found, and re-use the property from it.
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Different types of entities have different properties. One common property for many types of entities is "Image".
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Other types of objects have other properties.
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 ctrl+= plain English input EntityList[class] entities in a class EntityValue[entities,property] value of a property of an entity EntityProperties[type] list of properties for an entity type InputForm[entity] internal Wolfram Language representation of an entity
16.1Find the flag of Switzerland. »
Expected output:
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16.2Get an image of an elephant. »
Sample expected output:
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16.3Use the "Mass" property to generate a list of the masses of the planets. »
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16.4Make a bar chart of the masses of the planets. »
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16.5Make an image collage of images of the planets. »
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16.6Edge detect the flag of China. »
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16.7Find the height of the Empire State Building. »
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16.8Compute the height of the Empire State Building divided by the height of the Great Pyramid. »
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16.9Compute the elevation of Mount Everest divided by the height of the Empire State Building. »
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16.10Find the dominant colors in the painting The Starry Night»
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16.11Find the dominant colors in an image collage of the flag images of all countries in Europe. »
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16.12Make a pie chart of the GDP of countries in Europe. »
Sample expected output:
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Sample expected output:
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+16.1Make an image collage of the flags of all countries in Europe, using the "FlagImage" property. »
Sample expected output:
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+16.2Edge detect an image of the painting The Starry Night»
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+16.3Color negate the Mona Lisa painting. »
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Where does the Wolfram Language get its real-world data?
Its all from the central Wolfram Knowledgebase. Weve been building this knowledgebase for many years, carefully curating data from thousands of primary sources.
Is the data in the Wolfram Language regularly updated?
How accurate is the data in the Wolfram Language?
We go to a lot of trouble to make it as accurate as possible, and we check it extensively. But ultimately we often have to rely on what governments and other outside organizations report.
How should I refer to a particular entity?
However you want to. The Wolfram Language is set up to understand all common ways to refer to entities. (New York City, NYC, the big apple, etc., all work.)
How can I find all properties and values for a given entity?
Use entity["Dataset"] or entity["PropertyAssociation"].
It means the value youve asked for isnt known, or at least isnt in the Wolfram Knowledgebase. Use DeleteMissing to delete Missing[...] elements in a list.