| 用量 | 傳回 |
|---|---|
Image.arraySlice(axis, start, end, step) | 圖片 |
| 引數 | 類型 | 詳細資料 |
|---|---|---|
這個：input | 圖片 | 輸入陣列圖片。 |
axis | 整數，預設值為 0 | 軸到子集。 |
start | 圖片 (預設值：null) | 沿著「軸」的第一個切片座標 (含)。負數用於相對於陣列結尾定位切片開頭，其中 -1 從軸上的最後一個位置開始，-2 從倒數第二個位置開始，依此類推。起始索引必須有一個帶狀區域，或每個「輸入」帶狀區域各有一個帶狀區域。如果未設定或遮蓋這個引數的某些像素，該像素的切片就會從索引 0 開始。 |
end | 圖片 (預設值：null) | 停止擷取切片的座標 (不含)。根據預設，這會是指定軸的長度。負數可用來指定切片結尾相對於陣列結尾的位置，其中 -1 會排除最後一個位置，-2 會排除最後兩個位置，依此類推。結尾索引必須有一個帶，或每個「輸入」帶有一個帶。如果未在某個像素設定或遮蓋這個引數，該像素的切片會在最後一個索引之後結束。 |
step | 整數，預設值為 1 | 沿著「axis」的切片間隔；系統會從「start」(含) 到「end」(不含) 的每個「step」整數倍數位置取一個切片。必須為正數。 |
範例
程式碼編輯器 (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, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]).toArray(); print('1D array image (pixel)', sampArrImg(arrayImg1D)); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] // Get the first 3 elements. print('1D array image first 3 elements (pixel)', sampArrImg(arrayImg1D.arraySlice(0, 0, 3))); // [0, 1, 2] // Get the last 3 elements. print('1D array image last 3 elements (pixel)', sampArrImg(arrayImg1D.arraySlice(0, -3))); // [9, 10, 11] // Get elements at index positions 3 through 5 (0-based). print('1D array image elements at index positions 3 through 5 (pixel)', sampArrImg(arrayImg1D.arraySlice(0, 3, 6))); // [3, 4, 5] // Get elements at index positions 4 through end (0-based). print('1D array image elements at index positions 4 through end (pixel)', sampArrImg(arrayImg1D.arraySlice(0, 4))); // [4, 5, 6, 7, 8, 9, 10, 11] // Get elements using a step of 3. print('1D array image elements at a step of 3 (pixel)', sampArrImg(arrayImg1D.arraySlice(0, 0, null, 3))); // [0, 3, 6, 9] // 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, 1, 2, 3], // [4, 5, 6, 7], // [8, 9, 10, 11]] // Get the second row. print('2D array image second row (pixel)', sampArrImg(arrayImg2D.arraySlice(0, 1, 2))); // [[4, 5, 6, 7] // Get the second column. print('2D array image second column (pixel)', sampArrImg(arrayImg2D.arraySlice(1, 1, 2))); // [[1], // [5], // [9]] // Get all columns except the last. print('2D array image all columns except last (pixel)', sampArrImg(arrayImg2D.arraySlice(1, 0, -1))); // [[0, 1, 2], // [4, 5, 6], // [8, 9, 10]]
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, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]).toArray() print('1D array image (pixel):', samp_arr_img(array_img_1d).getInfo()) # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] # Get the first 3 elements. print('1D array image first 3 elements (pixel):', samp_arr_img(array_img_1d.arraySlice(0, 0, 3)).getInfo()) # [0, 1, 2] # Get the last 3 elements. print('1D array image last 3 elements (pixel):', samp_arr_img(array_img_1d.arraySlice(0, -3)).getInfo()) # [9, 10, 11] # Get elements at index positions 3 through 5 (0-based). print('1D array image elements at index positions 3 through 5 (pixel):', samp_arr_img(array_img_1d.arraySlice(0, 3, 6)).getInfo()) # [3, 4, 5] # Get elements at index positions 4 through end (0-based). print('1D array image elements at index positions 4 through end (pixel)', samp_arr_img(array_img_1d.arraySlice(0, 4)).getInfo()) # [4, 5, 6, 7, 8, 9, 10, 11] # Get elements using a step of 3. print('1D array image elements at a step of 3 (pixel)', samp_arr_img(array_img_1d.arraySlice(0, 0, None, 3)).getInfo()) # [0, 3, 6, 9] # 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, 1, 2, 3], # [4, 5, 6, 7], # [8, 9, 10, 11]] # Get the second row. print('2D array image second row (pixel):', samp_arr_img(array_img_2d.arraySlice(0, 1, 2)).getInfo()) # [[4, 5, 6, 7] # Get the second column. print('2D array image second column (pixel):', samp_arr_img(array_img_2d.arraySlice(1, 1, 2)).getInfo()) # [[1], # [5], # [9]] # Get all columns except the last. print('2D array image all columns except last (pixel):', samp_arr_img(array_img_2d.arraySlice(1, 0, -1)).getInfo()) # [[0, 1, 2], # [4, 5, 6], # [8, 9, 10]]