Variables:
last = . = (last printed number)
$bc
10+1+2+3
16
last*2
32
last
32
.
32
.+1
33
.+1
34
.+1
35
.+1
36
.
36
last
36
a=10
.
36
a+.
46
total=10+20+30+40+50
media=total/5
media
30
total
150
Archive for June, 2011
More bc tips
June 27, 2011bc tips
June 27, 2011Auto explicative tips for the command line calculator:
(base conversion and real numbers)
$bc
ibase=2
1001
9
1001+10
11
ibase=2
obase=2
100+1+1
110
3/2
1
scale=2
3/2
1.50
ibase=16
FF
255
FFFF
65535
obase=16
1
1
2
2
9
9
10
A
14
E
15
F
16
10
Future laptops could be powered by typing
June 27, 2011Generating frequency tones from command line
June 24, 2011apt-get install siggen
$ signalgen sine 1200
Toys
June 23, 2011PandaBoard, BeagleBoard-XM, mini2440
-
- dsc02567
-
- dsc02566
Converting photos to send by email
June 23, 2011mkdir new
for i in *JPG;
do
convert -resize 640×480 $i new/$i
done
Kinetic Resources
June 21, 2011GPU password cracking
June 16, 2011Insecure Cryptographic Storage
June 15, 2011Digital Signal processing resources
June 14, 2011I am almost finishing my Digital Signal Processing Course, but before returning the books to the library, I would like to list the ones that were helpful for future references.
Wavelets: The wavelet tutorial
(http://users.rowan.edu/~polikar/WAVELETS/WTpart1.html)
It explains clearly the basics of the Wavelet transform, getting you ready for more advanced texts.
Books:
5-Star book:
- Understanding Digital Signal Processing by Richard Lyons
I have no words to describe this book. Once you start reading it, you can’t stop. Everything is very well and clearly explained. I mean, very well! Each equation is described and explained and put in context. As the author says, most DSP writers think that the reader have a P.h.D in mathematics introducing formulas and theorems expecting that the reader is already used to those formulas.
I must say that I had no previous experience with DSP and I have serious troubles when it comes to math. But after reading this book, from cover to cover, I have a solid understanding of the major DSP topics such as IIR and FIR filters, convolution, DFT, FFT,
Z-Transform, Signals and Systems, Fourier Analysis, etc. I can even prove the convolution and Fourier theorems now!
Richard Lyons should win prizes for this book!
- Digital Signal Processing – Fundamentals and Applications by Li Tan Very clear and objective. Direct to the point with many examples and applications. The explanations are clear and easy to get, but are not detailed and most proves are omitted. In my opinion it’s a great book for undergraduate courses.
- Shaum’s Collection – Digital Signal Processing
Concepts and briefly introduced without long discussion and many, many problems are solved. It’s a secondary resource. You’ll won’t learn from this book alone.
- Signals & Systems – Oppenheim
- Very clear and basic explanations, but covers only the signals and systems (as the name says!) aspects
And now, the books I most fear:
- Digital Signal Processing – by Proakis and Manolakis
- Dicrete-Time Signal Processing – by Oppenheim
I don’t understand why most professors love these books. They are good references, and everyone says that these are the “reference books” on the subject. But sometimes i found very hard to understand magical formulas appearing from nowhere and gets simplified in a jiffy. I had trouble understanding these books when I first started studying, but after reading twice Lyon’s book, the concepts on these reference books became more clear and easy to understand, and the magical formulas where not so magical anymore.
