MATLAB: Editing a nyquist figure

Control System Toolboxfigurefrequencynyquistplot

How can I edit a nyquist figure or how can I plot a nyquist diagram using MATLAB such that it just consists positive frequencies and not negative ones ?

Best Answer

Run the nyquist command as usual:

nyquist([1],[1 2 1])

Then if you right click on the axes (the white part), a context menu will pop up and in the third option you can select not to show the negative frequencies.

Related Solutions

MATLAB: Extract values from Nyquist for negative frequencies

The Nyquist plot is symmetric, so the compex cojugate of the output would correspond to the negative frequencies.

[re_pos,im_pos,w_h] = nyquist(h);
re_neg =  re_pos;
im_neg = -im_pos;

MATLAB: Filter Butterworth

It will depend on what you are trying to do (low pass, highpass, band pass, band stop)

You have Ws hence your Wp will change depending on what kind of filter you want. More details about the specificatiosn and examples are given in the documentation

documentation: http://www.mathworks.com/help/toolbox/signal/ref/buttord.html

Wp-Passband corner frequency Wp, the cutoff frequency, is a scalar or a two-element vector with values between 0 and 1, with 1 corresponding to the normalized Nyquist frequency, π radians per sample.

Ws-Stopband corner frequency Ws, is a scalar or a two-element vector with values between 0 and 1, with 1 corresponding to the normalized Nyquist frequency.

Rp-Passband ripple, in decibels. This value is the maximum permissible passband loss in decibels.

Rs-Stopband attenuation, in decibels. This value is the number of decibels the stopband is down from the passband

Best Answer

Related Solutions

MATLAB: Extract values from Nyquist for negative frequencies

MATLAB: Filter Butterworth

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