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2.5 Graphics 83
2.5 Graphics
Mathematica has proven to be a powerful problem-solving environment for a large variety of
engineering tasks. One of many reasons which make Mathematica such a useful tool is that it
provides excellent support for visualizing the results of technical computations. Due to its freely
programmable graphics functionality the flexibility of adapting the graphics display to individual
applications is virtually unlimited. Analog Insydes extends Mathematica’s basic graphic capabilities
by adding special plotting functions for circuit analysis and design, including Bode, Nyquist, Nichol,
root locus plots, and transient waveforms.
2.5.1 Bode Plots
The Bode plot is perhaps the most commonly used graphing scheme for visualizing frequency
responses of linear analog systems. It consists of two separate charts which display magnitude and
phase of a transfer function on a logarithmic and a linear scale vs. frequency, the latter being scaled
logarithmically. The magnitude values are usually given in decibels (dB) and the phase values in
degrees.
In Analog Insydes, Bode plots are displayed using the command BodePlot (Section 3.9.1). With the
basic syntax
BodePlot[tfunc, frange]
you can plot the transfer function tfunc within the frequency range frange. The transfer function
must be a complex-valued function of the frequency variable fvar, and the frequency range a list of
the form {fvar, fstart, fend}. BodePlot also allows to plot several transfer functions simultaneously.
For this purpose, the first argument of BodePlot must be specified as a list of transfer functions.
BodePlot[{tfunc
, tfunc
, }, frange]
To demonstrate the Bode plot facility we define the following transfer function in terms of the
frequency variable s.
In[1]:=