D3.js geoLarrivee() Function

The D3.js geoLarrivee() function is used to interpolate between two geographic coordinates using the Larrivée interpolation method. This method calculates the shortest distance between two points on the globe by using a spherical model of the Earth.

Syntax

The syntax for using the geoLarrivee() function is as follows:

d3.geoLarrivee()

Description

The geoLarrivée() function returns an interpolator function that takes a value between 0 and 1 and returns the corresponding interpolated geographic coordinate.

var interpolate = d3.geoLarrivee()
    .source([lon1, lat1])
    .target([lon2, lat2]);

var interpolatedCoordinates = interpolate(0.5);

The .source() and .target() methods are used to set the two geographic coordinates that will be interpolated. The input domain of the returned interpolator function is a value between 0 and 1, representing the proportion of the distance between the two coordinates where the interpolated point will be located.

Example

var interpolate = d3.geoLarrivee()
    .source([-115.61, 34.20])
    .target([-74.00, 40.71]);

var interpolatedCoordinates = interpolate(0.5);

console.log(interpolatedCoordinates); // [-95.84744, 37.23751]

In this example, we create an interpolator function that interpolates between two points on the globe: San Diego, California and New York, New York, USA. We call the interpolator function with an input value of 0.5, indicating that we want to find the geographic coordinate that is halfway between the two points. The function returns an array with the interpolated longitude and latitude coordinates.

Conclusion

In conclusion, the D3.js geoLarrivee() function provides a convenient way to interpolate between two geographic coordinates using the Larrivée interpolation method. This method is useful when calculating the shortest distance between two points on the surface of the Earth using a spherical model.