X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Finterpolation.py;h=dc061077eda70879682048775c3ca69e423e9450;hb=2fa2a7a2f6a5d5f1628a4f5cf3301d5e7f670038;hp=5c8fa288de43c0ffa8b580cece5a0566945f88b9;hpb=94fb4e7b5ff5590a37043f65ed0acf7117ba3b35;p=sage.d.git diff --git a/mjo/interpolation.py b/mjo/interpolation.py index 5c8fa28..dc06107 100644 --- a/mjo/interpolation.py +++ b/mjo/interpolation.py @@ -44,6 +44,10 @@ def lagrange_coefficient(k, x, xs): A symbolic expression of one variable. + SETUP:: + + sage: from mjo.interpolation import lagrange_coefficient + TESTS:: sage: xs = [ -pi/2, -pi/6, 0, pi/6, pi/2 ] @@ -60,7 +64,7 @@ def lagrange_coefficient(k, x, xs): def lagrange_polynomial(x, xs, ys): """ - Return the Lagrange form of the interpolation polynomial in `x` of + Return the Lagrange form of the interpolating polynomial in `x` at the points (xs[k], ys[k]). INPUT: @@ -75,6 +79,10 @@ def lagrange_polynomial(x, xs, ys): A symbolic expression (polynomial) interpolating each (xs[k], ys[k]). + SETUP:: + + sage: from mjo.interpolation import lagrange_polynomial + TESTS:: sage: xs = [ -pi/2, -pi/6, 0, pi/6, pi/2 ] @@ -111,6 +119,10 @@ def lagrange_interpolate(f, x, xs): A polynomial in ``x`` which interpolates ``f`` at ``xs``. + SETUP:: + + sage: from mjo.interpolation import lagrange_interpolate + EXAMPLES: We're exact on polynomials of degree `n` if we use `n+1` points:: @@ -135,7 +147,11 @@ def divided_difference_coefficients(xs): Assuming some function `f`, compute the coefficients of the divided difference f[xs[0], ..., xs[n]]. - TESTS: + SETUP:: + + sage: from mjo.interpolation import divided_difference_coefficients + + TESTS:: sage: divided_difference_coefficients([0]) [1] @@ -166,6 +182,10 @@ def divided_difference(xs, ys): The (possibly symbolic) divided difference function. + SETUP:: + + sage: from mjo.interpolation import divided_difference + TESTS:: sage: xs = [0] @@ -183,7 +203,7 @@ def divided_difference(xs, ys): We try something entirely symbolic:: - sage: f = function('f', x) + sage: f = function('f')(x) sage: divided_difference([x], [f(x=x)]) f(x) sage: x1,x2 = SR.var('x1,x2') @@ -215,7 +235,11 @@ def newton_polynomial(x, xs, ys): A symbolic expression. - TESTS: + SETUP:: + + sage: from mjo.interpolation import lagrange_polynomial, newton_polynomial + + TESTS:: sage: xs = [ -pi/2, -pi/6, 0, pi/6, pi/2 ] sage: ys = map(sin, xs) @@ -304,7 +328,11 @@ def hermite_interpolant(x, xs, ys, y_primes): A symbolic expression. - TESTS: + SETUP:: + + sage: from mjo.interpolation import hermite_interpolant + + TESTS:: sage: xs = [ 0, pi/6, pi/2 ] sage: ys = map(sin, xs)