ee.Array.log

以元素为单位计算输入的自然对数。

用法返回
Array.log()数组
参数类型详细信息
此：input数组输入数组。

示例

代码编辑器 (JavaScript)

print(ee.Array([Math.pow(Math.E, -1), 1, Math.E]).log());  // [-1,0,1]

var start = 0.1;
var end = 6;
var points = ee.Array(ee.List.sequence(start, end, null, 50));
var values = points.log();

// Plot log() defined above.
var chart = ui.Chart.array.values(values, 0, points)
    .setOptions({
      viewWindow: {min: start, max: end},
      hAxis: {
        title: 'x',
        viewWindowMode: 'maximized',
        ticks: [
          {v: 0},
          {v: 3},
          {v: end}]
      },
      vAxis: {
        title: 'log(x)',
        ticks: [
          {v: -3},
          {v: 0},
          {v: 3}]
      },
      lineWidth: 1,
      pointSize: 0,
    });
print(chart);

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)

import math
import altair as alt
import pandas as pd

display(ee.Array([pow(math.e, -1), 1, math.e]).log())  # [-1,0,1]

start = 0.1
end = 6
points = ee.Array(ee.List.sequence(start, end, None, 50))
values = points.log()

df = pd.DataFrame({'x': points.getInfo(), 'log(x)': values.getInfo()})

# Plot log() defined above.
alt.Chart(df).mark_line().encode(
    x=alt.X('x', axis=alt.Axis(values=[0, 3, end])),
    y=alt.Y('log(x)', axis=alt.Axis(values=[-3, 0, 3]))
)