show_margins
============

display gain and phase margin and associated crossover frequencies



Calling Sequence
~~~~~~~~~~~~~~~~


::

    show_margins(h)
    show_margins(h,'bode')
    show_margins(h,'nyquist')




Arguments
~~~~~~~~~

:h a SISO linear system (see :`syslin`_).
:



Description
~~~~~~~~~~~

Given a SISO linear system in continuous or discrete time,
`show_margins` display gain and phase margin and associated crossover
frequencies on a bode (the defaut) or nyquist representation of the
frequency response of the system.



Examples
~~~~~~~~


::

    //continuous case
    h=`syslin`_('c',0.02909+0.11827*%s+0.12823*%s^2+0.35659*%s^3+0.256*%s^4+0.1*%s^5,..
                 0.0409+0.1827*%s+1.28225*%s^2+3.1909*%s^3+2.56*%s^4+%s^5);
    show_margins(h)  
    show_margins(h,'nyquist')
    
    //discrete case
    h = `syslin`_(0.1,0.01547+0.01599*%z ,%z^2-1.81*%z+0.9048)
    show_margins(h)
    show_margins(h,'nyquist')




See Also
~~~~~~~~


+ `p_margin`_ phase margin and associated crossover frequency
+ `g_margin`_ gain margin and associated crossover frequency
+ `bode`_ Bode plot
+ `nyquist`_ nyquist plot


.. _g_margin: g_margin.html
.. _p_margin: p_margin.html
.. _bode: bode.html
.. _nyquist: nyquist.html
.. _syslin: syslin.html