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authorFranciszek Malinka <franciszek.malinka@gmail.com>2021-10-05 21:49:54 +0200
committerFranciszek Malinka <franciszek.malinka@gmail.com>2021-10-05 21:49:54 +0200
commitc5fcf7179a83ef65c86c6a4a390029149e518649 (patch)
treed29ffc5b86a0d257453cedcf87d91a13d8bf3b0d /Semestr 3/anm/pracownia2/brut.jl
parentf8a88b6a4aba1f66d04711a9330eaba49a50c463 (diff)
Duzy commit ze smieciami
Diffstat (limited to 'Semestr 3/anm/pracownia2/brut.jl')
-rw-r--r--Semestr 3/anm/pracownia2/brut.jl177
1 files changed, 0 insertions, 177 deletions
diff --git a/Semestr 3/anm/pracownia2/brut.jl b/Semestr 3/anm/pracownia2/brut.jl
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--- a/Semestr 3/anm/pracownia2/brut.jl
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@@ -1,177 +0,0 @@
-using LinearAlgebra
-using Polynomials
-using Printf
-using OffsetArrays
-using FFTW
-
-function emptyArray(type, size)
- return OffsetVector{type}(undef, 0:(size - 1))
-end
-
-function naive_cc(f, N)
- a = emptyArray(Float64, Int(N) + 1)
- for j in 0.0:1.0:N
- for k in 0.0:1.0:N
- u = cos(k * pi / N)
- uj = cos(j * k * pi / N)
- val = f(u) * uj
- if k == 0 || k == N
- val /= 2.0
- end
- a[Int(j)] += val
- end
- end
- return a * (2.0 / N)
-end
-
-function naive_approx(f, N)
- b = emptyArray(Float64, N)
- a = naive_cc(f, N)
- a[0] /= 2.0
- a[N] /= 2.0
-
- print(a)
- result = 0.0
-
- for k in 0:2:N
- result += a[k] / Float64(1 - k * k)
- end
- return result * 2.0
-end
-
-function naive_approx2(f, N)
- b = emptyArray(Float64, N)
- N = Float64(N)
- a = naive_cc(f, N)
- result = 0.0
-
- for k in 1:1:Int(floor(N / 2.0))
- b[2 * k - 1] = a[2 * k - 2] - a[2 * k]
- b[2 * k - 1] /= (Float64(k) * 4.0 - 2.0)
- result += b[2 * k - 1]
- end
- return result * 2.0
-end
-
-function smart_cc(f, N)
- x = [cos(pi * i / N) for i in 0:N]
- fx = f.(x) / (2 * N)
- g = real(fft(vcat(fx, fx[N:-1:2])))
- a = [g[1] * 2; g[2:N] + g[(2 * N):-1:(N + 2)]; g[N + 1] * 2]
- return a
-end
-
-function clenshaw_curtis_coeffs(f, N)
- x = [cos(pi * i / N) for i in 0:N]
- fx = f.(x) / (2 * N)
- g = real(fft(vcat(fx, fx[N:-1:2])))
- return [g[1]; g[2:N] + g[(2 * N):-1:(N + 2)]; g[N + 1]]
-end
-
-function clenshaw_curtis(f, N)
- a = clenshaw_curtis_coeffs(f, N)
- w = zeros(length(a))
- w[1:2:end] = 2 ./ (1 .- (0:2:N).^2 )
- # w oraz a są malejące, więc lepiej dodawać ich iloczyny od końca
- LinearAlgebra.dot(reverse(w), reverse(a))
-end
-
-global MAX_ITER = 2^18
-
-function clenshaw_curtis_with_eps(f, eps)
- N = 4
- while N <= MAX_ITER
- res1 = clenshaw_curtis(f, N)
- res2 = clenshaw_curtis(f, N - 1)
- if abs(res1 - res2) < eps * res1 || N >= MAX_ITER
- return res1
- end
- N *= 2
- end
-end
-
-
-# zera n-tego wielomianu Czebyszewa
-function chebyshev_nodes(n)
- return [cos((2.0 * k - 1.0) * pi / (2.0 * n)) for k in 1:n]
-end
-
-# kwadratura Czebyszewa-Gaussa
-# współczynniki stałe równe π/N
-# węzły to zera n-tego wielomianu Czebyszewa
-function gauss_chebyshev(f, N)
- x = chebyshev_nodes(N)
- res = 0.0
- for i in 1:N
- res += f(x[i]) * sqrt(1.0 - x[i] * x[i])
- end
- return res * pi / N
-end
-
-# kwadratura Gaussa-Legendre'a:
-# współczynniki w_i = 2(q_1,i)^2, gdzie q_1,i to pierwsza współrzędna
-# i-tego wektora własnego macierzy trójprzekątniowej
-# węzły x_i to zera N-tego wielomianu Legendre'a
-function gauss_legendre(f, N)
- # wyliczanie wartości i wektorów własnych macierzy trójprzekątniowej
- # (Golub-Welsch algorithm)
- # wartości własne to zera wielomianu Legendre'a
- X, Q = eigen(SymTridiagonal(zeros(N), [n / sqrt(4.0n^2 - 1.0) for n = 1:N - 1]))
-
- res = 0.0
- for i in 1:N
- w = 2.0 * (Q[1, i])^2
- res += f(X[i]) * w
- end
-
- return res
-end
-
-# uruchamianie kwadratury dla funkcji f, N węzłów,
-# na przedziale (a, b)
-function quadrature(f, quadrature_fun, N=ITER, a=-1.0, b=1.0)
- return (b - a) / 2 * quadrature_fun(x -> f(x * (b - a) / 2 + (a + b) / 2), N)
-end
-
-# Testowanie-------------------------------------------------------------
-
-funs = [exp, x -> 1.0 / ((x - 1.01) * (x - 1.01)), x -> 10x^4 + 4x^3 + 2x - 1, x -> cos(1000.0x),
- x -> (3x^2 + 4) / (x - 1.1), abs, x -> 1.0, x -> cos(100.0x) * cos(100.0x), x -> 1 / (x^4 + x^2 + 0.9),
- x -> 1.0 / (1.0 + x^4), x -> 2.0 / (2.0 + sin(10pi * x))]
-
-# f - całka nieoznaczona
-# obliczanie całki oznaczonej na przedziale (a, b)
-function definete(f)
- return (a, b) -> f(b) - f(a)
-end
-
-
-# ręcznie policzone całki oznaczone (lub obliczone wyniki)
-# dla testowanych funkcji
-results = [definete(exp), definete(x -> 1.0 / (1.01 - x)), definete(x -> 2x^5 + x^4 + x^2 - x), definete(x -> sin(1000.0x) / 1000.0),
- definete(x -> 1.5x^2 + 3.3x + 7.63log(abs(x - 1.1))), definete(x -> (x >= 0) ? ((x^2) / 2.0) : (-(x^2) / 2.0)), definete(x -> x),
- definete(x -> (200.0x + sin(200.0x)) / 400.0), definete(x -> -0.278185log(x^2 - 0.947294x + 0.948683) +
- 0.278185log(x^2 + 0.947294x + 0.948683) + 0.309633atan(0.587487 * (2x - 0.947294)) + 0.309633atan(0.587487 * (2.0x + 0.947294))),
- definete(x -> 1.0 / (4.0 * sqrt(2)) * (-log(abs(x^2 - sqrt(2)x + 1)) + log(abs(x^2 + sqrt(2)x + 1)) - 2.0atan(1 - sqrt(2)x)
- + 2.0atan(1 + sqrt(2)x))), (a, b) -> 4.0 / sqrt(3)]
-
-
-function rel_error(a, b)
- return abs((a - b) / a)
-end
-
-function test(quadrature_fun, fun_nr, a=-1.0, b=1.0, N=ITER)
- my_res = quadrature(funs[fun_nr], quadrature_fun, N, a, b)
- rel_e = rel_error(results[fun_nr](a, b), my_res)
- abs_e = abs(results[fun_nr](a, b) - my_res)
-
- return (rel_e, abs_e)
-end
-
-function print_coefficients_of_cc(f, N, ile_pierwszych)
- a = clenshaw_curtis_coeffs(f, N)
- for i in 1:ile_pierwszych
- # println(string(i - 1, " & ", a[i], " \\\\"))
- @printf("%d & %.20f \\\\\n", i - 1, a[i])
- end
-end \ No newline at end of file