AI-generated Key Takeaways
-
The
ImageCollection.toDictionary()method extracts properties from a feature as a dictionary. -
By default,
toDictionary()extracts all non-system properties, but you can specify a list of properties to extract. -
The examples demonstrate how to use
toDictionary()in both JavaScript and Python to retrieve collection properties.
| Usage | Returns |
|---|---|
ImageCollection.
toDictionary
( properties
)
|
Dictionary |
| Argument | Type | Details |
|---|---|---|
|
this:
element
|
Element | The feature to extract the property from. |
properties
|
List, default: null | The list of properties to extract. Defaults to all non-system properties. |
Examples
Code Editor (JavaScript)
// A contrived, empty image collection for simple demonstration. var col = ee . ImageCollection ([]); print ( 'Collection without properties' , col ); // Set collection properties using a dictionary. col = col . set ({ project_name : 'biomass_tracking' , project_id : 3 , plot_ids : ee . Array ([ 7 , 11 , 20 ]) }); // Set collection properties using a series of key-value pairs. col = col . set ( 'project_year' , 2018 , 'rgb_vis' , 'false_color' ); print ( 'Collection with properties' , col ); // Get a dictionary of collection property keys and values. print ( 'Property keys and values (ee.Dictionary)' , col . toDictionary ()); // Get the value of a collection property. To use the result of // ee.ImageCollection.get in further computation, you need to cast it to the // appropriate class, for example, ee.Number(result) or ee.String(result). print ( 'Project ID (ambiguous object)' , col . get ( 'project_id' )); // Get the value of a string collection property as an ee.String object. print ( 'Project name (ee.String)' , col . getString ( 'project_name' )); // Get the value of a numeric collection property as an ee.Number object. print ( 'Project year (ee.Number)' , col . getNumber ( 'project_year' )); // Get the value of an ee.Array collection property as an ee.Array object. print ( 'Plot IDs (ee.Array)' , col . getArray ( 'plot_ids' ));
import ee import geemap.core as geemap
Colab (Python)
# A contrived, empty image collection for simple demonstration. col = ee . ImageCollection ([]) display ( 'Collection without properties:' , col ) # Set collection properties using a dictionary. col = col . set ({ 'project_name' : 'biomass_tracking' , 'project_id' : 3 , 'plot_ids' : ee . Array ([ 7 , 11 , 20 ]) }) # Set collection properties using a series of key-value pairs. col = col . set ( 'project_year' , 2018 , 'rgb_vis' , 'false_color' ) display ( 'Collection with properties:' , col ) # Get a dictionary of collection property keys and values. display ( 'Property keys and values (ee.Dictionary):' , col . toDictionary ()) # Get the value of a collection property. To use the result of # ee.ImageCollection.get in further computation, you need to cast it to the # appropriate class, for example, ee.Number(result) or ee.String(result). display ( 'Project ID (ambiguous object):' , col . get ( 'project_id' )) # Get the value of a string collection property as an ee.String object. display ( 'Project name (ee.String):' , col . getString ( 'project_name' )) # Get the value of a numeric collection property as an ee.Number object. display ( 'Project year (ee.Number):' , col . getNumber ( 'project_year' )) # Get the value of an ee.Array collection property as an ee.Array object. display ( 'Plot IDs (ee.Array):' , col . getArray ( 'plot_ids' ))
