ee.Array.atan

  • The Array.atan() method computes the arctangent in radians for each element of an input array.

  • This method takes an Array as input and returns an Array as output.

  • Examples are provided in both JavaScript and Python demonstrating the usage and plotting of the atan() function.

 On an element-wise basis, computes the arctangent in radians of the input.

UsageReturns
Array.atan()Array
ArgumentTypeDetails
this: inputArrayThe input array.

Examples

Code Editor (JavaScript)

print(ee.Array([-5]).atan());  // [-1.3734]
print(ee.Array([0]).atan());  // [0]
print(ee.Array([5]).atan());  // [1.3734]

var start = -5;
var end = 5;
var points = ee.Array(ee.List.sequence(start, end, null, 50));
var values = points.atan();

// Plot atan() defined above.
var chart = ui.Chart.array.values(values, 0, points)
    .setOptions({
      viewWindow: {min: start, max: end},
      hAxis: {
        title: 'x',
        viewWindowMode: 'maximized',
        ticks: [
          {v: start, f: start},
          {v: 0, f: 0},
          {v: end, f: end}]
      },
      vAxis: {
        title: 'atan(x)',
        ticks: [
          {v: -Math.PI / 2, f: '-π/2'},
          {v: 0, f: 0},
          {v: Math.PI / 2, f: 'π/2'}]
      },
      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([-5]).atan())  # [-1.3734]
display(ee.Array([0]).atan())  # [0]
display(ee.Array([5]).atan())  # [1.3734]

start = -5
end = 5
points = ee.Array(ee.List.sequence(start, end, None, 50))
values = points.atan()

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

# Plot atan() defined above.
alt.Chart(df).mark_line().encode(
    x=alt.X('x', axis=alt.Axis(values=[start, 0, end])),
    y=alt.Y('atan(x)', axis=alt.Axis(values=[-math.pi / 2, 0, math.pi / 2]))
)