- Function File:
**nyquist**(`sys`) - Function File:
**nyquist**(`sys1, sys2, ..., sysN`) - Function File:
**nyquist**(`sys1, sys2, ..., sysN, w`) - Function File:
**nyquist**(`sys1, 'style1', ..., sysN, 'styleN'`) - Function File: [
`re`,`im`,`w`] =**nyquist**(`sys`) - Function File: [
`re`,`im`,`w`] =**nyquist**(`sys, w`) Nyquist diagram of frequency response. If no output arguments are given, the response is printed on the screen.

**Inputs**`sys`- LTI system. Must be a single-input and single-output (SISO) system.
`w`- Optional vector of frequency values. If
`w`is not specified, it is calculated by the zeros and poles of the system. Alternatively, the cell`{wmin, wmax}`

specifies a frequency range, where`wmin`and`wmax`denote minimum and maximum frequencies in rad/s. `'style'`- Line style and color, e.g. 'r' for a solid red line or '-.k' for a dash-dotted
black line. See
`help plot`for details.

**Outputs**`re`- Vector of real parts. Has length of frequency vector
`w`. `im`- Vector of imaginary parts. Has length of frequency vector
`w`. `w`- Vector of frequency values used.

**See also:**bode, nichols, sigma.

Package: control