BesselJ[n,z]
给出第一类贝塞尔函数
.
BesselJ
BesselJ[n,z]
给出第一类贝塞尔函数
.
更多信息
- 数学函数,适宜于符号和数值运算.
是微分方程
的解. - BesselJ[n,z] 在复平面 z 上有分支切割,从
到
. - FullSimplify 和 FunctionExpand 含有 BesselJ 的变换规则.
- 对于一些特殊的参数,BesselJ 自动运算出精确值.
- BesselJ 可求任意数值精度的值.
- BesselJ 自动逐项作用于列表的各个元素.
- BesselJ 可与 Interval 和 CenteredInterval 对象一起使用. »
范例
打开所有单元 关闭所有单元基本范例 (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}]在 Infinity 的级数展开:
Series[BesselJ[0, x], {x, ∞, 3}]//Normal范围 (52)
数值运算 (6)
BesselJ[0, 4.0]N[BesselJ[0, 4], 50]BesselJ[0, 4.000000000000000000000000]BesselJ[7 / 3 + I, 4.5 - I]在高精度条件下高效运行 BesselJ:
BesselJ[0, 4`500]//TimingBesselJ[0, 4`50000];//Timing使用 Interval 和 CenteredInterval 对象计算最坏情况下的区间:
BesselJ[Interval[{0.5, 0.6}], Interval[{2.4, 2.5}]]BesselJ[1 / 2, CenteredInterval[2, 1 / 100]]或者使用 Around 计算一般情况下的统计区间:
BesselJ[2, Around[2, 0.01]]BesselJ[0.5, {{1, 2}, {3, 4}}]或使用 MatrixFunction 计算矩阵 BesselJ 函数:
MatrixFunction[BesselJ[0.5, #]&, {{1, 2}, {3, 4}}]特殊值 (3)
对于半整数指数,BesselJ 求解为初等函数:
Table[BesselJ[(2n + 1) / 2, x], {n, 0, 2}]Limit[BesselJ[n, x], x -> Infinity]Table[BesselJZero[0, x], {x, 3}]//N用 Solve 求
的第一个正零点:
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]]]可视化 (4)
绘制整数 (
) 和半整数 (
) 阶数的 BesselJ 函数:
Plot[{BesselJ[0, x], BesselJ[1, x], BesselJ[-1 / 2, x]}, {x, -7, 7}]绘制半整数阶 BesselJ 函数的实部和虚部:
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»]]函数属性 (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对于整数
,
是关于
的奇函数还是偶函数,取决于
是偶数还是奇数:
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 既不是非递增,也不是非递减:
Table[FunctionMonotonicity[BesselJ[n, z], z], {n, 5}]Table[FunctionMonotonicity[BesselJ[1 / n, z], z], {n, 5}]BesselJ 不是单射函数:
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 不是满射函数:
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 既不是非负,也不是非正:
Table[FunctionSign[BesselJ[n, z], z], {n, 4}]FunctionSingularities[BesselJ[n, z], z]//SimplifyFunctionDiscontinuities[BesselJ[n, z], z]//SimplifyBesselJ 既不凸,也不凹:
Table[FunctionConvexity[BesselJ[a, z], z], {a, 5}]TraditionalForm 格式:
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}]积分 (5)
Integrate[BesselJ[n, x], x]含有 BesselJ 的表达式的不定积分:
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}]级数展开式 (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 级数展开式的通项:
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 的渐近逼近:
Series[BesselJ[n, x], {x, ∞, 2}]//NormalSeries[BesselJ[n, x], {x, x0, 2}]// FullSimplifyBesselJ 可被应用于幂级数:
BesselJ[1 / 3, Log[1 + x] + O[x] ^ 2]积分变换 (4)
用 FourierTransform 计算傅立叶变换:
FourierTransform[BesselJ[0, t], t, ω]LaplaceTransform[BesselJ[n, t], t, s]HankelTransform[BesselY[n, r], r, s ]MellinTransform[BesselJ[n, x], x, s]函数恒等式和化简 (4)
用 FullSimplify 化简贝塞尔函数:
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]函数表示 (5)
用 BesselI 表示:
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]用 MeijerG 表示:
MeijerGReduce[BesselJ[n, x], x]Activate[%]用 DifferenceRoot 表示:
DifferenceRootReduce[BesselJ[k, z], k]应用 (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]夫琅禾费衍射 (Fraunhofer diffraction) 是发生在小菲涅尔数 (small Fresnel number) 极限下的衍射类型. 绘制圆形光圈的夫琅禾费衍射图案的强度与衍射角的关系:
Plot[2(BesselJ[1, 20Sin[θ]] / (20Sin[θ])) ^ 2, {θ, 0, π / 3}]开普勒方程描述了一个物体在椭圆轨道上的运动. 开普勒方程的近似解是截断的傅里叶正弦级数:
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}]属性和关系 (5)
用 FullSimplify 简化贝塞尔函数:
FullSimplify[x BesselJ[2, x] + x BesselJ[0, x]]Sum[ (-1)^kx^2k / (k!) ^ 2, {k, 0, ∞}]Integrate[ Cos[x Cos[2 π t]], {t, 0, 1}, Assumptions -> x > 0]求解含有 BesselJ 的表达式的极限:
Limit[(BesselJ[3, x]/Sin[x] - x), x -> 0]BesselJ 可被表示为 DifferentialRoot:
DifferentialRootReduce[BesselJ[n, x], x]BesselJ 的指数母函数:
ExponentialGeneratingFunction[BesselJ[n, k], n, x]可能存在的问题 (1)
技术笔记
-
▪
- 特殊函数 ▪
- 关于内部实现的一些注释
历史
1988年引入 (1.0) | 在以下年份被更新:1999 (4.0) ▪ 2000 (4.1) ▪ 2002 (4.2) ▪ 2021 (13.0) ▪ 2022 (13.1)
文本
Wolfram Research (1988),BesselJ,Wolfram 语言函数,https://reference.wolfram.com/language/ref/BesselJ.html (更新于 2022 年).
CMS
Wolfram 语言. 1988. "BesselJ." Wolfram 语言与系统参考资料中心. Wolfram Research. 最新版本 2022. https://reference.wolfram.com/language/ref/BesselJ.html.
APA
Wolfram 语言. (1988). BesselJ. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/ref/BesselJ.html 年
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: 11-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: 11-August-2026]}