BesselJ[n,z]
第1種ベッセル関数
を与える.
BesselJ
BesselJ[n,z]
第1種ベッセル関数
を与える.
詳細
- 記号操作・数値操作の両方に適した数学関数である.
において,微分方程式
が成り立つ.- BesselJ[n,z]は,複素 z 平面上,
〜
の範囲で不連続な分枝切断線を持つ. - FullSimplifyとFunctionExpandはBesselJの変換規則を含む.
- 特別な引数の場合,BesselJは,自動的に厳密値を計算する.
- BesselJは任意の数値精度で評価できる.
- BesselJは自動的にリストに縫い込まれる.
- BesselJはIntervalオブジェクトおよびCenteredIntervalオブジェクトに使うことができる. »
例題
すべて開く すべて閉じる例 (5)
BesselJ[0, 5.2]Plot[BesselJ[0, x], {x, 0, 50}]ComplexPlot3D[BesselJ[1 / 2, z], {z, -2 - 2I, 2 + 2I}, PlotLegends -> Automatic]Series[BesselJ[0, x], {x, 0, 10}]Infinityにおける級数展開:
Series[BesselJ[0, x], {x, ∞, 3}]//Normalスコープ (52)
数値評価 (6)
BesselJ[0, 4.0]N[BesselJ[0, 4], 50]BesselJ[0, 4.000000000000000000000000]BesselJ[7 / 3 + I, 4.5 - I]BesselJを高精度で効率よく評価する:
BesselJ[0, 4`500]//TimingBesselJ[0, 4`50000];//TimingIntervalオブジェクトとCenteredIntervalオブジェクトを使って最悪の場合に保証される区間を計算する:
BesselJ[Interval[{0.5, 0.6}], Interval[{2.4, 2.5}]]BesselJ[1 / 2, CenteredInterval[2, 1 / 100]]Aroundを使って平均的な場合の統計区間を計算することもできる:
BesselJ[2, Around[2, 0.01]]BesselJ[0.5, {{1, 2}, {3, 4}}]MatrixFunctionを使って行列のBesselJ関数を計算することもできる:
MatrixFunction[BesselJ[0.5, #]&, {{1, 2}, {3, 4}}]特定の値 (3)
半整数の指標について,BesselJを評価すると初等関数になる:
Table[BesselJ[(2n + 1) / 2, x], {n, 0, 2}]Limit[BesselJ[n, x], x -> Infinity]Table[BesselJZero[0, x], {x, 3}]//NSolveを使って
の最初の正の零点を求める:
sol = Solve[BesselJ[0, x] == 0 && 0 < x < 3, x]//Nxzero = x /. First@sol;
Plot[BesselJ[0, x], {x, -1, 8}, Epilog -> Style[Point[{xzero, BesselJ[0, xzero]}], Red, PointSize[Large]]]可視化 (4)
整数次(
)および半整数次(
)について,BesselJ関数をプロットする:
Plot[{BesselJ[0, x], BesselJ[1, x], BesselJ[-1 / 2, x]}, {x, -7, 7}]BesselJ関数の実部と虚部を半整数次数についてプロットする:
ReImPlot[{BesselJ[1 / 2, x], BesselJ[3 / 2, x]}, {x, -3, 3}]ComplexContourPlot[Re[BesselJ[0, z]], {z, -4 - 4I, 8 + 4I}, IconizedObject[«PlotOptions»]]ComplexContourPlot[Im[BesselJ[0, z]], {z, -4 - 4I, 8 + 4I}, IconizedObject[«PlotOptions»]]ComplexContourPlot[Re[BesselJ[-1 / 4, z]], {z, -4 - 4I, 8 + 4I}, IconizedObject[«PlotOptions»]]ComplexContourPlot[Im[BesselJ[-1 / 4, z]], {z, -4 - 4I, 8 + 4I}, IconizedObject[«PlotOptions»]]関数の特性 (12)
FunctionDomain[BesselJ[0, x], x]FunctionDomain[BesselJ[0, z], z, Complexes]FunctionDomain[BesselJ[1 / 2, x], x]FunctionDomain[BesselJ[1 / 2, z], z, Complexes]FunctionRange[BesselJ[0, x], x, y]//QuietFunctionRange[BesselJ[1, x], x, y]//Quiet整数
について,
は
が偶数か奇数かによって
についての偶関数あるいは奇関数である:
BesselJ[0, -z]BesselJ[1, -z]FullSimplify[BesselJ[n, z] == (-1)^n BesselJ[n, -z], n∈ℤ]Table[FunctionAnalytic[BesselJ[n, z], z], {n, -2, 2}]Table[FunctionAnalytic[BesselJ[n, z], z], {n, -(3/2), (3/2)}]BesselJは非減少でも非増加でもない:
Table[FunctionMonotonicity[BesselJ[n, z], z], {n, 5}]Table[FunctionMonotonicity[BesselJ[1 / n, z], z], {n, 5}]BesselJは単射ではない:
Table[FunctionInjective[BesselJ[n, z], z], {n, 5}]Table[FunctionInjective[BesselJ[1 / n, z], z], {n, 5}]Plot[{BesselJ[1, z], BesselJ[2, z], BesselJ[1 / 3, z], .2}, {z, 0, 15}]BesselJは全射ではない:
Table[FunctionSurjective[BesselJ[n, z], z], {n, 5}]Table[FunctionSurjective[BesselJ[1 / n, z], z], {n, 5}]Plot[{BesselJ[1, z], BesselJ[2, z], BesselJ[1 / 3, z], 1}, {z, 0, 15}]BesselJは非負でも非正でもない:
Table[FunctionSign[BesselJ[n, z], z], {n, 4}]
は,
が非整数のとき,
(
を含む可能性あり)について特異である:
FunctionSingularities[BesselJ[n, z], z]//SimplifyFunctionDiscontinuities[BesselJ[n, z], z]//SimplifyBesselJは凸でも凹でもない:
Table[FunctionConvexity[BesselJ[a, z], z], {a, 5}]TraditionalFormによる表示:
BesselJ[n, r]//TraditionalForm微分 (3)
D[BesselJ[n, x], x]derivs = Table[D[BesselJ[n, x], {x, k}], {k, 1, 3}]//FullSimplifyPlot[Evaluate[derivs /. n -> 0], {x, -2, 2}, PlotLegends -> {"First Derivative", "Second Derivative", "Third Derivative"}]ReImPlot[Evaluate[derivs /. n -> 1 / 2], {x, -2, 2}, PlotLegends -> {"First Derivative", "Second Derivative", "Third Derivative"}]D[BesselJ[n, x], {x, j}]積分 (5)
Integrateを使ってBesselJの不定積分を計算する:
Integrate[BesselJ[n, x], x]BesselJを含む式の不定積分:
Integrate[Sin[x] BesselJ[n, x], x]Integrate[BesselJ[n, x], {x, 0, Infinity}]Integrate[BesselJ[1, x], {x, -10, 10}]Integrate[BesselJ[0, x], {x, -10, 10}]2 Integrate[BesselJ[0, x], {x, 0, 10}]級数展開 (6)
Series[BesselJ[0, x], {x, 0, 7}]terms = Normal@Table[Series[BesselJ[0, x], {x, 0, m}], {m, 2, 7, 2}];
Plot[{BesselJ[0, x], terms}, {x, -8, 8}, PlotRange -> {All, {-1, 1.5}}]BesselJの級数展開における一般項:
SeriesCoefficient[BesselJ[0, x], {x, 0, n}]Series[BesselJ[-1 / 2, x], {x, 0, 7}]terms = Normal@Table[Series[BesselJ[-1 / 2, x], {x, 0, m}], {m, 2, 7, 2}];
Plot[{BesselJ[-1 / 2, x], terms}, {x, 0, 10}, PlotRange -> {All, {-1, 1.5}}]BesselJの漸近近似:
Series[BesselJ[n, x], {x, ∞, 2}]//NormalSeries[BesselJ[n, x], {x, x0, 2}]// FullSimplifyBesselJはベキ級数に適用できる:
BesselJ[1 / 3, Log[1 + x] + O[x] ^ 2]積分変換 (4)
FourierTransformを使ってフーリエ(Fourier)変換を計算する:
FourierTransform[BesselJ[0, t], t, ω]LaplaceTransform[BesselJ[n, t], t, s]HankelTransform[BesselY[n, r], r, s ]MellinTransform[BesselJ[n, x], x, s]関数の恒等式と簡約 (4)
FullSimplifyを使ってベッセル関数を簡約する:
FullSimplify[x BesselJ[2, x] + x BesselJ[0, x]]BesselJ[n - 1, z] BesselJ[-n, z] + BesselJ[1 - n, z] BesselJ[n, z] == (2 Sin[n π]/π z)//FullSimplifyFullSimplify[z (BesselJ[n - 1, z] + BesselJ[n + 1, z]) == 2n BesselJ[n, z]]FullSimplify[BesselJ[-n, z] == (-1)^n BesselJ[n, z], n∈ℤ]関数表現 (5)
BesselIを介した表現:
FullSimplify[(z^n/(I z)^n)BesselI[n, I z]]Sum[ (-1)^k((x/2))^2k / (k!) ^ 2, {k, 0, ∞}]Integrate[ Cos[x Cos[2 π t]], {t, 0, 1}, Assumptions -> x > 0]MeijerGによる表現:
MeijerGReduce[BesselJ[n, x], x]Activate[%]DifferenceRootによる表現:
DifferenceRootReduce[BesselJ[k, z], k]アプリケーション (3)
DSolve[ x^2y''[x] + x y'[x] + (x - n)(x + n)y[x] == 0, y[x], x]DSolve[(a + x Cot[x]) y[x] + (x + 2 x^2 Cot[x]) Derivative[1][y][x] + x^2 Derivative[2][y][x] == 0, y[x], x]フラウンホーファー(Fraunhofer)回析は小さいフレネル(Fresnel)数の極限で出現する回析の一種である.円形開口対回析角のフラウンホーファー回析パターン強度をプロットする:
Plot[2(BesselJ[1, 20Sin[θ]] / (20Sin[θ])) ^ 2, {θ, 0, π / 3}]Keplerの方程式は楕円軌道における物体の動きを説明する.Keplerの方程式の解を切断フーリエ正弦級数として近似する:
aKeplerE[ϵ_, m_] = m + Sum[(2/n)BesselJ[n, n ϵ]Sin[n m], {n, 1, 12}];eKeplerE[ϵ_Real, m_Real] := Block[{x}, x /. FindRoot[x - ϵ Sin[x] == m, {x, m}]]Plot[eKeplerE[0.5, m] - aKeplerE[0.5, m], {m, 0, 4Pi}]特性と関係 (5)
FullSimplifyを使ってベッセル関数を簡約する:
FullSimplify[x BesselJ[2, x] + x BesselJ[0, x]]SumおよびIntegrateはBesselJを生成することがある:
Sum[ (-1)^kx^2k / (k!) ^ 2, {k, 0, ∞}]Integrate[ Cos[x Cos[2 π t]], {t, 0, 1}, Assumptions -> x > 0]BesselJを含む式の極限を求める:
Limit[(BesselJ[3, x]/Sin[x] - x), x -> 0]BesselJはDifferentialRootとして表すことができる:
DifferentialRootReduce[BesselJ[n, x], x]BesselJの指数母関数:
ExponentialGeneratingFunction[BesselJ[n, k], n, x]考えられる問題 (1)
関連するガイド
-
▪
- ベッセル(Bessel)関連関数 ▪
- 数学関数 ▪
- 特殊関数 ▪
- 科学的モデル ▪
- 光学で使用される関数 ▪
- 分離可能な座標系の関数
履歴
1988 で導入 (1.0) | 1999 で更新 (4.0) ▪ 2000 (4.1) ▪ 2002 (4.2) ▪ 2021 (13.0) ▪ 2022 (13.1)
テキスト
Wolfram Research (1988), BesselJ, Wolfram言語関数, https://reference.wolfram.com/language/ref/BesselJ.html (2022年に更新).
CMS
Wolfram Language. 1988. "BesselJ." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2022. https://reference.wolfram.com/language/ref/BesselJ.html.
APA
Wolfram Language. (1988). BesselJ. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/BesselJ.html
BibTeX
@misc{reference.wolfram_2026_besselj, author="Wolfram Research", title="{BesselJ}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/BesselJ.html}", note=[Accessed: 10-August-2026]}
BibLaTeX
@online{reference.wolfram_2026_besselj, organization={Wolfram Research}, title={BesselJ}, year={2022}, url={https://reference.wolfram.com/language/ref/BesselJ.html}, note=[Accessed: 10-August-2026]}