ee.Image.arraySort

    Sorts elements of each array pixel along one axis.
    Usage Returns
    Image. arraySort ( keys ) Image
    Argument Type Details
    this: image
    		Image Array image to sort.
    keys
    		Image, default: null Optional keys to sort by. If not provided, the values are used as the keys. The keys can only have multiple elements along one axis, which determines the direction to sort in.

    Examples

    Code Editor (JavaScript) 

     // A function to print arrays 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 with length 12. 
 var 
  
 arrayImg1D 
  
 = 
  
 ee 
 . 
 Image 
 ([ 
 0 
 , 
  
 10 
 , 
  
 6 
 , 
  
 5 
 , 
  
 4 
 , 
  
 7 
 , 
  
 11 
 , 
  
 1 
 , 
  
 2 
 , 
  
 9 
 , 
  
 8 
 , 
  
 3 
 ]). 
 toArray 
 (); 
 print 
 ( 
 '1D array image (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg1D 
 )); 
 // [0, 10, 6, 5, 4, 7, 11, 1, 2, 9, 8, 3] 
 // Sort the 1D array in ascending order. 
 var 
  
 arrayImg1DSorted 
  
 = 
  
 arrayImg1D 
 . 
 arraySort 
 (); 
 print 
 ( 
 '1D array image sorted (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg1DSorted 
 )); 
 // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] 
 // You can use another array image to control sorting. The order of values 
 // in the optional keys array translates to relative position in the input 
 // array. For example, here is a keys array image with non-sequential values in 
 // descending order, it will reverse the order of the input array; make the 
 // last position first and the first position last. 
 var 
  
 keys1D 
  
 = 
  
 ee 
 . 
 Image 
 ([ 
 99 
 , 
  
 98 
 , 
  
 50 
 , 
  
 45 
 , 
  
 23 
 , 
  
 18 
 , 
  
 9 
 , 
  
 8 
 , 
  
 7 
 , 
  
 5 
 , 
  
 2 
 , 
  
 0 
 ]). 
 toArray 
 (); 
 print 
 ( 
 '1D array image keys (pixel)' 
 , 
  
 sampArrImg 
 ( 
 keys1D 
 )); 
 // [99, 98, 50, 45, 23, 18, 9, 8, 7, 5, 2, 0] 
 var 
  
 arrayImg1DSortedKeys 
  
 = 
  
 arrayImg1D 
 . 
 arraySort 
 ( 
 keys1D 
 ); 
 print 
 ( 
 '1D array image sorted by keys (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg1DSortedKeys 
 )); 
 // [3, 8, 9, 2, 1, 11, 7, 4, 5, 6, 10, 0] 
 // To sort a 2D array, the keys array image is required. 
 // Create a 2D array image with 3 rows and 4 columns. 
 var 
  
 arrayImg2D 
  
 = 
  
 arrayImg1D 
 . 
 arrayReshape 
 ( 
 ee 
 . 
 Image 
 ([ 
 3 
 , 
  
 4 
 ]). 
 toArray 
 (), 
  
 2 
 ); 
 print 
 ( 
 '2D array image (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg2D 
 )); 
 // [[0, 10,  6, 5], 
 //  [4,  7, 11, 1], 
 //  [2,  9,  8, 3]] 
 // Only a single axis can be sorted at a time. Here, we reverse sort along rows. 
 // There are 4 elements in each row, so we construct an 1x4 array image. 
 var 
  
 keys2Drows 
  
 = 
  
 ee 
 . 
 Image 
 ([ 
 3 
 , 
  
 2 
 , 
  
 1 
 , 
  
 0 
 ]). 
 toArray 
 (). 
 toArray 
 ( 
 1 
 ). 
 arrayTranspose 
 (); 
 print 
 ( 
 '2D array image row keys (pixel)' 
 , 
  
 sampArrImg 
 ( 
 keys2Drows 
 )); 
 // [[3, 2, 1, 0]] 
 var 
  
 arrayImg2DSortedRows 
  
 = 
  
 arrayImg2D 
 . 
 arraySort 
 ( 
 keys2Drows 
 ); 
 print 
 ( 
 '2D array image sorted rows (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg2DSortedRows 
 )); 
 // [[5,  6, 10, 0], 
 //  [1, 11,  7, 4], 
 //  [3,  8,  9, 2]] 
 // Reverse sort along columns, create a 3x1 keys array image with values in 
 // descending order. 
 var 
  
 keys2Dcols 
  
 = 
  
 ee 
 . 
 Image 
 ([ 
 2 
 , 
  
 1 
 , 
  
 0 
 ]). 
 toArray 
 (). 
 toArray 
 ( 
 1 
 ); 
 print 
 ( 
 '2D array image column keys (pixel)' 
 , 
  
 sampArrImg 
 ( 
 keys2Dcols 
 )); 
 // [[2], 
 //  [1], 
 //  [0]] 
 var 
  
 arrayImg2DSortedCols 
  
 = 
  
 arrayImg2D 
 . 
 arraySort 
 ( 
 keys2Dcols 
 ); 
 print 
 ( 
 '2D array image sorted cols (pixel)' 
 , 
  
 sampArrImg 
 ( 
 arrayImg2DSortedCols 
 )); 
 // [[2,  9,  8, 3], 
 //  [4,  7, 11, 1], 
 //  [0, 10,  6, 5]]

    Python setup

    See the Python Environment page for information on the Python API and using geemap for interactive development.

     import 
  
 ee 
 import 
  
 geemap.core 
  
 as 
  
 geemap

    Colab (Python) 

     # A function to print arrays 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 with length 12. 
 array_img_1d 
 = 
 ee 
 . 
 Image 
 ([ 
 0 
 , 
 10 
 , 
 6 
 , 
 5 
 , 
 4 
 , 
 7 
 , 
 11 
 , 
 1 
 , 
 2 
 , 
 9 
 , 
 8 
 , 
 3 
 ]) 
 . 
 toArray 
 () 
 print 
 ( 
 '1D array image (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_1d 
 ) 
 . 
 getInfo 
 ()) 
 # [0, 10, 6, 5, 4, 7, 11, 1, 2, 9, 8, 3] 
 # Sort the 1D array in ascending order. 
 array_img_1d_sorted 
 = 
 array_img_1d 
 . 
 arraySort 
 () 
 print 
 ( 
 '1D array image sorted (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_1d_sorted 
 ) 
 . 
 getInfo 
 ()) 
 # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] 
 # You can use another array image to control sorting. The order of values 
 # in the optional keys array translates to relative position in the input 
 # array. For example, here is a keys array image with non-sequential values in 
 # descending order, it will reverse the order of the input array; make the 
 # last position first and the first position last. 
 keys_1d 
 = 
 ee 
 . 
 Image 
 ([ 
 99 
 , 
 98 
 , 
 50 
 , 
 45 
 , 
 23 
 , 
 18 
 , 
 9 
 , 
 8 
 , 
 7 
 , 
 5 
 , 
 2 
 , 
 0 
 ]) 
 . 
 toArray 
 () 
 print 
 ( 
 '1D array image keys (pixel):' 
 , 
 samp_arr_img 
 ( 
 keys_1d 
 ) 
 . 
 getInfo 
 ()) 
 # [99, 98, 50, 45, 23, 18, 9, 8, 7, 5, 2, 0] 
 array_img_1d_sorted_keys 
 = 
 array_img_1d 
 . 
 arraySort 
 ( 
 keys_1d 
 ) 
 print 
 ( 
 '1D array image sorted by keys (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_1d_sorted_keys 
 ) 
 . 
 getInfo 
 ()) 
 # [3, 8, 9, 2, 1, 11, 7, 4, 5, 6, 10, 0] 
 # To sort a 2D array, the keys array image is required. 
 # Create a 2D array image with 3 rows and 4 columns. 
 array_img_2d 
 = 
 array_img_1d 
 . 
 arrayReshape 
 ( 
 ee 
 . 
 Image 
 ([ 
 3 
 , 
 4 
 ]) 
 . 
 toArray 
 (), 
 2 
 ) 
 print 
 ( 
 '2D array image (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_2d 
 ) 
 . 
 getInfo 
 ()) 
 # [[0, 10,  6, 5], 
 #  [4,  7, 11, 1], 
 #  [2,  9,  8, 3]] 
 # Only a single axis can be sorted at a time. Here, we reverse sort along rows. 
 # There are 4 elements in each row, so we construct an 1x4 array image. 
 keys_2d_rows 
 = 
 ee 
 . 
 Image 
 ([ 
 3 
 , 
 2 
 , 
 1 
 , 
 0 
 ]) 
 . 
 toArray 
 () 
 . 
 toArray 
 ( 
 1 
 ) 
 . 
 arrayTranspose 
 () 
 print 
 ( 
 '2D array image row keys (pixel):' 
 , 
 samp_arr_img 
 ( 
 keys_2d_rows 
 ) 
 . 
 getInfo 
 ()) 
 # [[3, 2, 1, 0]] 
 array_img_2d_sorted_rows 
 = 
 array_img_2d 
 . 
 arraySort 
 ( 
 keys_2d_rows 
 ) 
 print 
 ( 
 '2D array image sorted rows (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_2d_sorted_rows 
 ) 
 . 
 getInfo 
 ()) 
 # [[5,  6, 10, 0], 
 #  [1, 11,  7, 4], 
 #  [3,  8,  9, 2]] 
 # Reverse sort along columns, create a 3x1 keys array image with values in 
 # descending order. 
 keys_2d_cols 
 = 
 ee 
 . 
 Image 
 ([ 
 2 
 , 
 1 
 , 
 0 
 ]) 
 . 
 toArray 
 () 
 . 
 toArray 
 ( 
 1 
 ) 
 print 
 ( 
 '2D array image column keys (pixel):' 
 , 
 samp_arr_img 
 ( 
 keys_2d_cols 
 ) 
 . 
 getInfo 
 ()) 
 # [[2], 
 #  [1], 
 #  [0]] 
 array_img_2d_sorted_cols 
 = 
 array_img_2d 
 . 
 arraySort 
 ( 
 keys_2d_cols 
 ) 
 print 
 ( 
 '2D array image sorted cols (pixel):' 
 , 
 samp_arr_img 
 ( 
 array_img_2d_sorted_cols 
 ) 
 . 
 getInfo 
 ()) 
 # [[2,  9,  8, 3], 
 #  [4,  7, 11, 1], 
 #  [0, 10,  6, 5]]
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