ee.Array.log

AI-generated Key Takeaways

• The Array.log() method computes the natural logarithm of each element in an input array.

• The input to the Array.log() method must be an Array.

• The method returns an Array containing the natural logarithms of the input array's elements.

On an element-wise basis, computes the natural logarithm of the input.

Usage	Returns
Array.log()	Array

Argument	Type	Details
this: input	Array	The input array.

Examples

Code Editor (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 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)

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]))
)