ee.Image.arrayGet

系統會為每個頻帶建立同名的輸出頻帶，並從該頻帶的輸入多維度像素中擷取指定位置的值。

用量	傳回
Image.arrayGet(position)	圖片

引數	類型	詳細資料
這個：image	圖片	要從中取得元素的陣列。
position	圖片	要取得的元素座標。純量頻帶的數量必須與輸入圖片的維度數量相同。

範例

程式碼編輯器 (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, 2, 3, 4, 5]).toArray();
print('1D array image (pixel)', sampArrImg(arrayImg1D));
// [0, 1, 2, 3, 4, 5]

// Get the array value at a given position. Here we target the 4th element.
var position1D = ee.Image([3]);
var selectedElement1D = arrayImg1D.arrayGet(position1D);
print('Element at position [3] (4th element)', sampArrImg(selectedElement1D));
// [3]

// 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, 2],
//  [3, 4, 5]]

// Get the array element value at axis-0, position 0 and axis-1, position 2.
var position2D = ee.Image([0, 2]);
var selectedElement2D = arrayImg2D.arrayGet(position2D);
print('Element at position [0, 2]', sampArrImg(selectedElement2D));
// 2

Python 設定

請參閱 Python 環境頁面，瞭解 Python API 和如何使用 geemap 進行互動式開發。

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, 2, 3, 4, 5]).toArray()
print('1D array image (pixel):', samp_arr_img(array_img_1d).getInfo())
# [0, 1, 2, 3, 4, 5]

# Get the array value at a given position. Here we target the 4th element.
position_1d = ee.Image([3])
selected_element_1d = array_img_1d.arrayGet(position_1d)
print(
    'Element at position [3] (4th element):',
    samp_arr_img(selected_element_1d).getInfo()
)
# [3]

# Create a 2D 2x3 array image (reshape the 1D 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],
#  [3, 4, 5]]

# Get the array element value at axis-0, position 0 and axis-1, position 2.
position_2d = ee.Image([0, 2])
selected_element_2d = array_img_2d.arrayGet(position_2d)
print(
    'Element at position [0, 2]:',
    samp_arr_img(selected_element_2d).getInfo()
)
# 2