ee.Image.arrayDotProduct

计算输入图像各波段中每对 1 维数组的点积。

用法返回
Image.arrayDotProduct(image2)图片
参数类型详细信息
此：image1图片一维向量的第一个数组映像。
image2图片一维向量的第二个数组图片。

示例

代码编辑器 (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');
}

// A 1D array image.
var arrayImg1Da = ee.Image([0, 1, 2]).toArray();
print('1D array image A (pixel)', sampArrImg(arrayImg1Da));
// [0, 1, 2]

// A second 1D array image of the same length.
var arrayImg1Db = ee.Image([3, 4, 5]).toArray();
print('1D array image B (pixel)', sampArrImg(arrayImg1Db));
// [3, 4, 5]

// Calculate the dot product for the two 1D arrays.
var test = arrayImg1Da.arrayDotProduct(arrayImg1Db);
print('A⋅B = 0(3) + 1(4) + 2(5) = ', sampArrImg(test));
// 14

Python 设置

如需了解 Python API 和如何使用 geemap 进行交互式开发，请参阅 Python 环境页面。

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')

# A 1D array image.
array_img_1d_a = ee.Image([0, 1, 2]).toArray()
print('1D array image A (pixel):', samp_arr_img(array_img_1d_a).getInfo())
# [0, 1, 2]

# A second 1D array image of the same length.
array_img_1d_b = ee.Image([3, 4, 5]).toArray()
print('1D array image B (pixel):', samp_arr_img(array_img_1d_b).getInfo())
# [3, 4, 5]

# Calculate the dot product for the two 1D arrays.
test = array_img_1d_a.arrayDotProduct(array_img_1d_b)
print('A⋅B = 0(3) + 1(4) + 2(5) = ', samp_arr_img(test).getInfo())
# 14