ee.Array.atan

  • Array.atan() calculates the element-wise arctangent (in radians) of an input array.

  • The function accepts an array as input and returns an array of the same size with the computed arctangent values.

  • Results are within the range of -π/2 to π/2 radians.

  • This function can be effectively visualized using charts for understanding the relationship between input values and their corresponding arctangent.

 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]))
)