AI-generated Key Takeaways
-
The
Image.arrayArgmax()function computes the positional indices of the maximum value in an image of array values. -
If there are multiple occurrences of the maximum value, the indices of the first occurrence are returned.
-
The function returns an
Imageobject. -
The input
thisargument must be anImage.
| Usage | Returns |
|---|---|
Image.
arrayArgmax
()
|
Image |
| Argument | Type | Details |
|---|---|---|
|
this:
image
|
Image | The input image. |
Examples
Code Editor (JavaScript)
// A function to print the array for a selected pixel in the following examples. function sampArrImg ( arrImg ) { var point = ee . Geometry . Point ([ - 121 , 42 ]); return arrImg . sample ( point , 500 ). first (). get ( 'array' ); } // Create a 1D array image. var arrayImg1D = ee . Image ([ 0 , 1 , 5 , 2 , 3 , 4 ]). toArray (); print ( '1D array image (pixel)' , sampArrImg ( arrayImg1D )); // [0, 1, 5, 2, 3, 4] // Get the position of the maximum value in a 1D array. var maxValue1D = arrayImg1D . arrayArgmax (); print ( 'Position of the maximum 1D array value' , sampArrImg ( maxValue1D )); // [2] // Create a 2D 2x3 array image (reshape the 1D array image). var arrayImg2D = arrayImg1D . arrayReshape ( ee . Image ([ 2 , 3 ]). toArray (), 2 ); print ( '2D 2x3 array image (pixel)' , sampArrImg ( arrayImg2D )); // [[0, 1, 5], // [2, 3, 4]] // Get the position of the maximum value in a 2D array. var maxValue2D = arrayImg2D . arrayArgmax (); print ( 'Position of the maximum 2D array value' , sampArrImg ( maxValue2D )); // [0, 2]
import ee import geemap.core as geemap
Colab (Python)
# A function to print the array for a selected pixel in the following examples. def samp_arr_img ( arr_img ): point = ee . Geometry . Point ([ - 121 , 42 ]) return arr_img . sample ( point , 500 ) . first () . get ( 'array' ) # Create a 1D array image. array_img_1d = ee . Image ([ 0 , 1 , 5 , 2 , 3 , 4 ]) . toArray () display ( '1D array image (pixel):' , samp_arr_img ( array_img_1d )) # [0, 1, 5, 2, 3, 4] # Get the position of the maximum value in a 1D array. max_value_1d = array_img_1d . arrayArgmax () display ( 'Position of the maximum 1D array value:' , samp_arr_img ( max_value_1d ) ) # [2] # Create a 2D 2x3 array image (reshape the 1D array image). array_img_2d = array_img_1d . arrayReshape ( ee . Image ([ 2 , 3 ]) . toArray (), 2 ) display ( '2D 2x3 array image (pixel):' , samp_arr_img ( array_img_2d )) # [[0, 1, 5], # [2, 3, 4]] # Get the position of the maximum value in a 2D array. max_value_2d = array_img_2d . arrayArgmax () display ( 'Position of the maximum 2D array value:' , samp_arr_img ( max_value_2d ) ) # [0, 2]
