AI-generated Key Takeaways
-
The
toListmethod returns elements of a collection as a list. -
It can fetch a specified number of elements (
count) and optionally discard elements from the start (offset). -
Using
toListon large collections can consume significant time and memory, potentially leading to errors.
| Usage | Returns |
|---|---|
ImageCollection.
toList
(count, offset
)
|
List |
| Argument | Type | Details |
|---|---|---|
|
this:
collection
|
FeatureCollection | The input collection to fetch. |
count
|
Integer | The maximum number of elements to fetch. |
offset
|
Integer, default: 0 | The number of elements to discard from the start. If set, (offset + count) elements will be fetched and the first offset elements will be discarded. |
Examples
Code Editor (JavaScript)
// Note: ee.ImageCollection.toList may take a lot of time and memory to run, // since it must generate all of the results in order to gather them into a // list. Large collections and/or complex computations can produce memory // limitation errors. // A Landsat 8 TOA image collection (1 year of images at a specific point). var col = ee . ImageCollection ( 'LANDSAT/LC08/C02/T1_TOA' ) . filterBounds ( ee . Geometry . Point ( - 90.70 , 34.71 )) . filterDate ( '2020-01-01' , '2021-01-01' ); print ( 'Image collection' , col ); // Get the first 3 images as a list of images. var imgListFirst3 = col . toList ( 3 ); print ( 'First 3 images' , imgListFirst3 ); // Get the second 3 images as a list of images (use the offset parameter). var imgListSecond3 = col . toList ( 3 , 3 ); print ( 'Second 3 images' , imgListSecond3 );
import ee import geemap.core as geemap
Colab (Python)
# Note: ee.ImageCollection.toList may take a lot of time and memory to run, # since it must generate all of the results in order to gather them into a # list. Large collections and/or complex computations can produce memory # limitation errors. # A Landsat 8 TOA image collection (1 year of images at a specific point). col = ee . ImageCollection ( 'LANDSAT/LC08/C02/T1_TOA' ) . filterBounds ( ee . Geometry . Point ( - 90.70 , 34.71 )) . filterDate ( '2020-01-01' , '2021-01-01' ) display ( 'Image collection:' , col ) # Get the first 3 images as a list of images. img_list_first3 = col . toList ( 3 ) display ( 'First 3 images:' , img_list_first3 ) # Get the second 3 images as a list of images (use the offset parameter). img_list_second3 = col . toList ( 3 , 3 ) display ( 'Second 3 images:' , img_list_second3 )
