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 6.
var arrayImg1D = ee.Image([0, 1, 2, 4, 0, 5]).toArray();
print('1D array image (pixel)', sampArrImg(arrayImg1D));
// [0, 1, 2, 4, 0, 5]
// Create a mask using a relational operator to mask values greater than 2.
var mask1D = arrayImg1D.lte(2);
print('1D mask for greater than value 2 (pixel)', sampArrImg(mask1D));
// [1, 1, 1, 0, 1, 0]
var arrayImg1DMask = arrayImg1D.arrayMask(mask1D);
print('1D array image mask (pixel)', sampArrImg(arrayImg1DMask));
// [0, 1, 2, 0]
// Self mask the 1D array image. Value zero will be masked out.
var arrayImg1DselfMask = arrayImg1D.arrayMask(arrayImg1D);
print('1D array image self mask (pixel)', sampArrImg(arrayImg1DselfMask));
// [1, 2, 4, 5]
// Create a 2D array image.
var arrayImg2D = arrayImg1D.arrayReshape(ee.Image([2, 3]).toArray(), 2);
print('2D 2x3 array image (pixel)', sampArrImg(arrayImg2D));
// [[0, 1, 2],
// [4, 0, 5]]
// Slice out a row to use as a column mask.
var rowAsMaskForCols = arrayImg2D.arraySlice(0, 1, 2);
print('2D mask for cols (pixel)', sampArrImg(rowAsMaskForCols));
// [[4, 0, 5]]
var arrayImg2DMaskCols = arrayImg2D.arrayMask(rowAsMaskForCols);
print('2D array image cols masked (pixel)', sampArrImg(arrayImg2DMaskCols));
// [[0, 2],
// [4, 5]]
// Slice out a column to use as a row mask.
var colAsMaskForRows = arrayImg2D.arraySlice(1, 1, 2);
print('2D mask for rows (pixel)', sampArrImg(colAsMaskForRows));
// [[1],
// [0]]
var arrayImg2DMaskRows = arrayImg2D.arrayMask(colAsMaskForRows);
print('2D array image rows masked (pixel)', sampArrImg(arrayImg2DMaskRows));
// [[0, 1, 2]]
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 6.
array_img_1d = ee.Image([0, 1, 2, 4, 0, 5]).toArray()
print('1D array image (pixel):', samp_arr_img(array_img_1d).getInfo())
# [0, 1, 2, 4, 0, 5]
# Create a mask using a relational operator to mask values greater than 2.
mask_1d = array_img_1d.lte(2)
print(
'1D mask for greater than value 2 (pixel):',
samp_arr_img(mask_1d).getInfo()
)
# [1, 1, 1, 0, 1, 0]
array_img1d_mask = array_img_1d.arrayMask(mask_1d)
print('1D array image mask (pixel):', samp_arr_img(array_img1d_mask).getInfo())
# [0, 1, 2, 0]
# Self mask the 1D array image. Value zero will be masked out.
array_img_1d_self_mask = array_img_1d.arrayMask(array_img_1d)
print(
'1D array image self mask (pixel):',
samp_arr_img(array_img_1d_self_mask).getInfo()
)
# [1, 2, 4, 5]
# Create a 2D array image.
array_img_2d = array_img_1d.arrayReshape(ee.Image([2, 3]).toArray(), 2)
print('2D 2x3 array image (pixel):', samp_arr_img(array_img_2d).getInfo())
# [[0, 1, 2],
# [4, 0, 5]]
# Slice out a row to use as a column mask.
row_as_mask_for_cols = array_img_2d.arraySlice(0, 1, 2)
print('2D mask for cols (pixel):', samp_arr_img(row_as_mask_for_cols).getInfo())
# [[4, 0, 5]]
array_img_2d_mask_cols = array_img_2d.arrayMask(row_as_mask_for_cols);
print(
'2D array image cols masked (pixel):',
samp_arr_img(array_img_2d_mask_cols).getInfo()
)
# [[0, 2],
# [4, 5]]
# Slice out a column to use as a row mask.
col_as_mask_for_rows = array_img_2d.arraySlice(1, 1, 2)
print('2D mask for rows (pixel):', samp_arr_img(col_as_mask_for_rows).getInfo())
# [[1],
# [0]]
array_img_2d_mask_rows = array_img_2d.arrayMask(col_as_mask_for_rows)
print(
'2D array image rows masked (pixel):',
samp_arr_img(array_img_2d_mask_rows).getInfo()
)
# [[0, 1, 2]]