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\documentclass[a4paper,11pt,final]{article}
\usepackage{hyperref}
\usepackage{graphicx}
\usepackage{minted}
\begin{document}
\title{Pweave Example - Frequency response of a moving average filter}
\author{Matti Pastell \\
\url{http://mpastell.com}}
\maketitle
\textbf{Create 11 point moving average filter and plot its frequency response and print the values.}
<<>>=
from pylab import *
import scipy.signal as signal
#A function to plot frequency and phase response
def mfreqz(b,a=1):
w,h = signal.freqz(b,a)
h = abs(h)
return(w/max(w), h)
@
\textbf{Make the impulse response function and use terminal formatted output (=doctest block.)}
<<term = True>>=
n = 11.
n
b = repeat(1/n, n)
b
@
\textbf{Calculate the frequency response and plot it:}
<<fig = True, caption = 'Frequency response of an 11 point moving average filter'>>=
w, h = mfreqz(b)
#Plot the function
plot(w,h,'k')
ylabel('Amplitude')
xlabel(r'Normalized Frequency (x$\pi$rad/sample)')
show()
@
\begin{table}
\caption{The first 10 values of the frequency response (w,h) as a table, notice that the code is hidden in the output document.}
\begin{center}
\begin{tabular}{ c | c }
\hline
\textbf{Amplitude} & \textbf{Frequency} \\ \hline
<<results = 'rst', echo = False>>=
print
for i in range(10):
print (round(h[i],2) , '&', round(w[i],2), r'\\')
@
\end{tabular}
\end{center}
\end{table}
\end{document}
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