Lagrange Interpolation: Difference between revisions

=={{header|Julia}}==

Note the Polynomials module prints polynomials in order from degree 0 to n rather than n to zero degree.

<syntaxhighlight lang="julia">using Polynomials, SpecialPolynomials

const pts = [[1, 1], [2, 4], [3, 1], [4, 5]]

const xs = first.(pts)

const ys = last.(pts)

const p = Lagrange(xs, ys)

@show p Polynomial(p)

</syntaxhighlight>{{out}}

<pre>

p = Lagrange(1⋅ℓ_0(x) + 4⋅ℓ_1(x) + 1⋅ℓ_2(x) + 5⋅ℓ_3(x))

Polynomial(p) = Polynomial(-21.0 + 35.83333333333333*x - 16.0*x^2 + 2.1666666666666665*x^3)

</pre>