The one-line program to be written in a text editor must have
t**2 and not t^2.
... \( v_0 \) in mathematics becomes v0 in the program. (Not v_0.)
%0xd is not an integer padded with x leading zeros, but an integer written
with a minimum field width of x, where any leading spaces are replaced
by zeros.
The printout does not correspond to the show code. The correct printout is
Jan: 56.6 Feb: 72.7 Mar: 116.5 Apr: 153.2 May: 191.1 Jun: 198.5 Jul: 193.8 Aug: 184.3 Sep: 138.3 Oct: 104.6 Nov: 67.4 Dec: 52.4
The code can also be simplified
monthly_mean = []
n = len(data) # no of years
for m in range(12): # counter for month indices
s = 0 # sum
for y in data: # loop over "rows" (first index) in data
s += y[m] # add value for month m
monthly_mean.append(s/n)
In the program c2f.py, the print statement has a wrong formatting
of the F(C) value: %.51f must read %5.1f, i.e., the same formatting
as used for the C value.
Heading in Section 3.1.5 should be Function argument or global variable? (or instead of of).
In Exercise 3.6, Equation (3.10), the sum must be \( \sum_{i=0}^{n-1} \).
The terminal output for the integral \( \int_0^{\pi/2}\sin x\,dx \) should read
1, not 0.583009.
In the mymod.py module, an import sys is needed in the test block before
print add1(float(sys.argv[1])).
The last code showing the test block of the interest module needs two
corrections: division by 365 if the expression for years and an f
in the print statement:
if __name__ == '__main__':
import sys
p = float(sys.argv[1])
years = days(1, 2, p)/365.0
print 'With p=%.2f it takes %.f1 years to double' % (p, years)
The computational example in this section involves the parameters
A0=2 and A=1, but it should be the other way around: A0=1 and A=2
(otherwise the interest rate becomes negative).
export PYTH=$HOME/software/lib/pymodules:$PATH
should be
export PATH=$HOME/software/lib/pymodules:$PATH
In Exercise 4.17, the reference to the program user_formula.py
should be integrate.py. The name of the resulting program is
then better named integrate2.py than user_formula2.py.
In the first code block, x3 = mat(x).transpose() should be
x3 = mat(x1).transpose().
End of first paragraph: Sun is to be replaced by Apple.
Last code block,
station = line.split('</strong>')[0].split('<strong>')[0]
must be
station = line.split('</strong>')[0].split('<strong>')[1]
The argument in the raise ValueError call, after if c*d <= 0, needs
a final % other.
The title of the chapter should be Random numbers and simple games.
Exercise 8.13: Since \( 4\leq n\leq 10 \) balls are drawn, one must investigate cases where \( n\in [4,10] \), say \( n=4,7.10 \) (and not \( n=1,5,10,20 \) which does not make sense).
The last line of the integrate_ode.py program should not contain
u'(t)=t**3, but read
print "Numerical solution of u'(t)=%s: %.4f" % \
(f_formula, integrate(T, n, u0))
The four terminal output sessions below are then also wrong: instead of
u'(t)=t**3 it should be u'(t)=t**exp(t**2).
Exercise E.1: The exact solution is \( u(t)=0.2e^{0.1t} \).
== Page 768 ===
Exercise E.24: The first constant on the right-hand sides of equations (E.70) and (E.72) must be 3 and 4, not 2 and 3.
Below the equation with \( I(t+\Delta t) \), it must read \( \Delta t\rightarrow 0 \) (not \( \infty \)).
Exercise E.42: The last element of the returned list in the
ProblemSIR.__call__ method should not have a minus sign; it should
be self.nu(t)*I.
Exercise E.46: A value for \( I(0) \) is not given. Set \( I(0)=0 \).
The text says "The import statements can actually be dropped since
functions from numpy and matplotlib are imported by default when
running the notebook in the browser or by supplying the command-line
argument --pylab when starting notebooks locally on your
machine.". Now, the use of --pylab is discouraged. Also, the
functions from numpy and matplotlib are not any longer
automatically imported - you have to do that explicitly.
The recommended way of using IPython notebooks with numpy and
matplotlib is to do
import numpy as np
import matplotlib.pyplot as plt
%matplitlib inline
If you want the notebook to behave more as Matlab and not use
the np and plt interface, you can instead write
%pylab
To succesfully execute the c2f.py program, cmd must be python c2f.y 21
or ./c2f.py 21 (if c2f.py is an executable file) unless . is in
the user's PATH variable.
Under Split file or folder name, the directory name user in the text
should be replaced by /home/hpl according to the interactive session.