matlab中相位和角度命令之间的差异

Question

Matlab中相位和角度命令有什么区别？对于相同的输入,似乎给出了不同的结果

参考:

Matlab帮助阶段

PHASE  Computes the phase of a complex vector

    PHI=phase(G)

    G is a complex-valued row vector and PHI is returned as its
    phase (in radians), with an effort made to keep it continuous
    over the pi-borders.

Matlab帮助角度

ANGLE  Phase angle.
    ANGLE(H) returns the phase angles, in radians, of a matrix with
    complex elements.  

    Class support for input X:
       float: double, single

另外,请您简单解释一下uwrap命令的用途究竟是什么？

Answer 1

首先,ANGLE命令来自MATLAB核心,来自系统识别工具箱的PHASE.

ANGLE命令总是给出范围[-pi,pi]的结果.

PHASE命令更复杂.例如,如果输入矢量中有两个相邻点,相位接近pi

X=[-1+0.1i -1-0.1i]

phase(X)命令将给出第二个值大于pi的答案(相位值之间的差值应小于pi).

此时,angle(X)命令将为第二个参数提供接近-pi的值(将值包装到范围[-pi,pi]中).例如

phase(X(2)) = angle(X(2)) + 2*pi