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mathematics_basic_for_ML
  • README
  • README
    • Summary
    • Geometry
      • EulerAngle
      • Gimbal lock
      • Quaternion
      • RiemannianManifolds
      • RotationMatrix
      • SphericalHarmonics
    • Information
      • Divergence
      • 信息熵 entropy
    • LinearAlgebra
      • 2D仿射变换(2D Affine Transformation)
      • 2DTransformation
      • 3D变换(3D Transformation)
      • ComplexTransformation
      • Conjugate
      • Hessian
      • IllConditioning
      • 逆变换(Inverse transform)
      • SVD
      • det
      • eigendecomposition
      • 矩阵
      • norm
      • orthogonal
      • special_matrix
      • trace
      • vector
    • Mathematics
      • Complex
      • ExponentialDecay
      • average
      • calculus
      • convex
      • derivative
      • 距离
      • function
      • space
      • Formula
        • euler
        • jensen
        • taylor
        • trigonometric
    • Numbers
      • 几何级数
      • SpecialNumbers
    • NumericalComputation
      • ConstrainedOptimization
      • GradientDescent
      • Newton
      • Nominal
      • ODE_SDE
      • Preprocessing
    • Probability
      • bayes
      • distribution
      • expectation_variance
      • 贝叶斯公式
      • functions
      • likelihood
      • mixture_distribution
      • 一些术语
      • probability_distribution
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Complex

PreviousMathematicsNextExponentialDecay

Last updated 2 years ago

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一个复数可以在复空间上表示: 复数也可以用

虚数的单位:在数学领域用i,在工程领域用j

令$z = x + iy$,则 模:$|r| = \sqrt{x^2 + y^2}$ 辐角:$\tan \theta = \frac{y}{x}$ 共轭复数:$\bar z = x - iy$ 极坐标:$z = re^{i\theta}$

一些公式:

z1⋅z2=(x1x2−y1y2)+i(x1y2+x2y1)z1z2=z1zˉ2z2zˉ2=x1x2+y1y2x22+y22+−x1y2+x2y1x22+y22∣z1−z2∣=(x1−x2)2+(y1−y2)2\begin{aligned} z_1 \cdot z_2 = (x_1x_2 - y_1y_2) + i(x_1y_2 + x_2y_1) \\ \frac{z_1}{z_2} = \frac{z_1\bar z_2}{z_2\bar z_2} = \frac{x_1x_2 + y_1y_2}{x_2^2+y_2^2} + \frac{-x_1y_2 + x_2y_1}{x_2^2+y_2^2} \\ |z_1 - z_2| = \sqrt{(x_1-x_2)^2 + (y_1-y_2)^2} \end{aligned}z1​⋅z2​=(x1​x2​−y1​y2​)+i(x1​y2​+x2​y1​)z2​z1​​=z2​zˉ2​z1​zˉ2​​=x22​+y22​x1​x2​+y1​y2​​+x22​+y22​−x1​y2​+x2​y1​​∣z1​−z2​∣=(x1​−x2​)2+(y1​−y2​)2​​

复变函数:以复数为自变量的函数

复变函数求导: 先把函数的结果用一个复数表达出来,实部和虚部都是关于变量的表达式,然后分别对实部和虚部求导 参考连接:https://zhuanlan.zhihu.com/p/108998452

复指数函数
欧拉公式