函数变换 对数变换(Logarithmic transformation) x=ab →lgx=lga+lgb x=a"bmIgx=nlga+mlgb 查表 School of Mechanical Engineering ME369-lecture 3.0 Shanghai Jiao Tong University Fall 2015 复数(Complex) 5=0-j0 r=G2+0 Magnitude模 B=arctan-,0∈(-π，π]Phase相角 S=σ+j0 s=r(cos0+jsine) j=万 joimaginary part o=rcos0 rectangular form 虚部 o=rsine 直角坐标形式 Phasor(Euler)form 相位矢量形式 real part 0 实部 s=reio 6 e1=cos0+jsin0 Polar form Euler's theorem 极坐标形式 欧拉公式 School of Mechanical Engineering ME369-lecture 3.0 Shanghal Jiao Tong University Fall 2015 22 BE315-Lecture 3.0 Fall 2011 ME369-lecture 3.0 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University x  ab n m x  a b lg x  lga  lgb lg x  nlga  mlgb 对数变换（Logarithmic transformation) 查表 函数变换 BE315-Lecture 3.0 Fall 2011 ME369-lecture 3.0 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 复数（Complex） s    j 2 2 arctan , ( , ] r                   Magnitude 模 Phase 相角 s  r(cos  jsin) cos sin j e j      Euler’s theorem 欧拉公式 j s re   rectangular form 直角坐标形式 cos sin r r          Phasor(Euler) form 相位矢量形式 * 1 j   Polar form 极坐标形式 s    j real part 实部 imaginary part 虚部 r 