ee.Array.asin

  • Array.asin() calculates the arcsine of each element in an input array.

  • The function returns a new array with the calculated arcsine values in radians.

  • Input values should be within the range of -1 to 1, inclusive.

  • The output values will be within the range of -π/2 to π/2 radians.

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

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

Examples

Code Editor (JavaScript)

print(ee.Array([-1]).asin());  // [-π/2]
print(ee.Array([0]).asin());  // [0]
print(ee.Array([1]).asin());  // [π/2]

var start = -1;
var end = 1;
var points = ee.Array(ee.List.sequence(start, end, null, 50));
var values = points.asin();

// Plot asin() 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: 'asin(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([-1]).asin())  # [-π/2]
display(ee.Array([0]).asin())  # [0]
display(ee.Array([1]).asin())  # [π/2]

start = -1
end = 1
points = ee.Array(ee.List.sequence(start, end, None, 50))
values = points.asin()

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

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