m_circle
========

plots the complex plane iso-gain contours of y/(1+y) (obsolete)



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


::

    m_circle()
    m_circle(gain)




Arguments
~~~~~~~~~

:gain vector of gains (in DB). The default value is
    :gain =[-12 -8 -6 -5 -4 -3 -2 -1.4 -1 -.5 0.25 0.5 0.7 1 1.4 2 2.3 3 4
      5 6 8 12]
    :

:



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

`m_circle` draws the iso-gain contours given by then `gain` argument
in the complex plane (Re,Im).

The default value for `gain` is:

`[-12 -8 -6 -5 -4 -3 -2 -1.4 -1 -.5 0.25 0.5 0.7 1 1.4 2 2.3 3 4 5 6 8
12]`

`m_circle` is used with `nyquist`.

This function is superseded by the `hallchart`_ function.



Examples
~~~~~~~~


::

    //Example 1 :
    s=`poly`_(0,'s')
    h=`syslin`_('c',(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01))
    `nyquist`_(h,0.01,100,'(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01)')
    m_circle();
    //Example 2:
    `clf`_();
    h1=h*`syslin`_('c',(s^2+2*0.1*15.1*s+228.01)/(s^2+2*0.9*15*s+225))
    `nyquist`_([h1;h],0.01,100,['h1';'h'])
    m_circle([-8 -6 -4]);




See Also
~~~~~~~~


+ `nyquist`_ nyquist plot
+ `chart`_ Nichols chart
+ `black`_ Black-Nichols diagram of a linear dynamical system


.. _black: black.html
.. _chart: chart.html
.. _nyquist: nyquist.html
.. _hallchart: hallchart.html