ee.Array.cat

  • ee.Array.cat() combines multiple arrays into a single array.

  • The axis parameter specifies the dimension along which the concatenation occurs (defaults to 0).

  • Input arrays must have the same dimensionality and be of the same length in all dimensions except the concatenation axis.

  • This function is useful for merging or extending array data in Earth Engine.

 Concatenates multiple arrays into a single array along the given axis. Each array must have the same dimensionality and the same length on all axes except the concatenation axis.

UsageReturns
ee.Array.cat(arrays, axis)Array
ArgumentTypeDetails
arraysListArrays to concatenate.
axisInteger, default: 0Axis to concatenate along.

Examples

Code Editor (JavaScript)

// Requires an explicit PixelType if no data.
var empty = ee.Array([], ee.PixelType.int8());  // Empty []
var one = ee.Array([1]);
var two = ee.Array([2]);

print(ee.Array.cat([empty]));  // []
print(ee.Array.cat([empty, empty]));  // []
print(ee.Array.cat([empty, one]));  // [1]
print(ee.Array.cat([one, empty]));  // [1]
print(ee.Array.cat([one, two]));  // [1, 2]

print(ee.Array.cat([one, two], 0));  // [1, 2]
print(ee.Array.cat([one, two], 1));  // [[1,2]]

var a = ee.Array([0, 1, 2]);
var b = ee.Array([3, 4, 5]);
print(ee.Array.cat([a, b]));  // [0,1,2,3,4,5]
print(ee.Array.cat([a, b], 0));  // [0,1,2,3,4,5]
print(ee.Array.cat([a, b], 1));  // [[0,3],[1,4],[2,5]]

var c = ee.Array([[0], [1], [2]]);
var d = ee.Array([[3], [4], [5]]);
print(ee.Array.cat([c, d]));  // [[0],[1],[2],[3],[4],[5]]
print(ee.Array.cat([c, d], 0));  // [[0],[1],[2],[3],[4],[5]]
print(ee.Array.cat([c, d], 1));  // [[0,3],[1,4],[2,5]]
print(ee.Array.cat([c, d], 2));  // [[[0,3]],[[1,4]],[[2,5]]]

var e = ee.Array([[[0, 1], [2, 3]], [[4, 5], [6, 7]]]);
var f = ee.Array([[[10, 11], [12, 13]], [[14, 15], [16, 17]]]);

// [[[0,1],[2,3]]
//  [[4,5],[6,7]]
//  [[10,11],[12,13]]
//  [[14,15],[16,17]]
print(ee.Array.cat([e, f], 0));

// [[[0,1],[2,3],[10,11],[12,13]]
//  [[4,5],[6,7],[14,15],[16,17]]]
print(ee.Array.cat([e, f], 1));

// [[[0,1,10,11],[2,3,12,13]]
//  [[4,5,14,15],[6,7,16,17]]]
print(ee.Array.cat([e, f], 2));

// [[[[0,10],[1,11]],[[2,12],[3,13]]]
//  [[[4,14],[5,15]],[[6,16],[7,17]]]]
print(ee.Array.cat([e, f], 3));

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)

# Requires an explicit PixelType if no data.
empty = ee.Array([], ee.PixelType.int8())  # []
one = ee.Array([1])
two = ee.Array([2])

display(ee.Array.cat([empty]))  # []
display(ee.Array.cat([empty, empty]))  # []
display(ee.Array.cat([empty, one]))  # [1]
display(ee.Array.cat([one, empty]))  # [1]
display(ee.Array.cat([one, two]))  # [1, 2]

display(ee.Array.cat([one, two], 0))  # [1, 2]
display(ee.Array.cat([one, two], 1))  # [[1, 2]]

a = ee.Array([0, 1, 2])
b = ee.Array([3, 4, 5])
display(ee.Array.cat([a, b]))  # [0, 1, 2, 3, 4, 5]
display(ee.Array.cat([a, b], 0))  # [0, 1, 2, 3, 4, 5]
display(ee.Array.cat([a, b], 1))  # [[0, 3], [1, 4], [2, 5]]

c = ee.Array([[0], [1], [2]])
d = ee.Array([[3], [4], [5]])
display(ee.Array.cat([c, d]))  # [[0], [1], [2], [3], [4], [5]]
display(ee.Array.cat([c, d], 0))  # [[0], [1], [2], [3], [4], [5]]
display(ee.Array.cat([c, d], 1))  # [[0, 3], [1, 4], [2, 5]]
display(ee.Array.cat([c, d], 2))  # [[[0, 3]], [[1, 4]], [[2, 5]]]

e = ee.Array([[[0, 1], [2, 3]], [[4, 5], [6, 7]]])
f = ee.Array([[[10, 11], [12, 13]], [[14, 15], [16, 17]]])

# [[[0, 1], [2, 3]]
#  [[4, 5], [6, 7]]
#  [[10, 11], [12, 13]]
#  [[14, 15], [16, 17]]
display(ee.Array.cat([e, f], 0))

# [[[0, 1], [2, 3], [10, 11], [12, 13]]
#  [[4, 5], [6, 7], [14, 15], [16, 17]]]
display(ee.Array.cat([e, f], 1))

# [[[0, 1, 10, 11], [2, 3, 12, 13]]
#  [[4, 5, 14, 15], [6, 7, 16, 17]]]
display(ee.Array.cat([e, f], 2))

# [[[[0, 10], [1, 11]], [[2, 12], [3, 13]]]
#  [[[4, 14], [5, 15]], [[6, 16], [7, 17]]]]
display(ee.Array.cat([e, f], 3))