ee.Array.sin

  • Array.sin() calculates the sine of each element within an input array, with the input values expected to be in radians.

  • It returns a new array containing the calculated sine values for each corresponding element of the original array.

  • This function is useful for mathematical computations and signal processing tasks on array data within the Earth Engine platform, demonstrated with examples in JavaScript and Python.

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

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

Examples

Code Editor (JavaScript)

var π = Math.PI;
print(ee.Array([-π]).sin());  // [Almost zero]
print(ee.Array([-π / 2.0]).sin());  // [-1]
print(ee.Array([0]).sin());  // [0]
print(ee.Array([π / 2.0]).sin());  // [1]
print(ee.Array([π]).sin());  // [Almost zero]

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

// Plot sin() 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: '-π'},
          {v: 0, f: 0},
          {v: end, f: '-π'}]
      },
      vAxis: {
        title: 'sin(x)',
        ticks: [
          {v: -1, f: -1},
          {v: 0, f: 0},
          {v: 1, f: 1}]
      },
      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

π = math.pi

display(ee.Array([-π]).sin())  # [Almost zero]
display(ee.Array([-π / 2.0]).sin())  # [-1]
display(ee.Array([0]).sin())  # [0]
display(ee.Array([π / 2.0]).sin())  # [1]
display(ee.Array([π]).sin())  # [Almost zero]

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

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

# Plot sin() defined above.
alt.Chart(df).mark_line().encode(
    x=alt.X('x', axis=alt.Axis(values=[start, 0, end])),
    y=alt.Y('sin(x)', axis=alt.Axis(values=[-1, 0, 1]))
)