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Scientific Computing
IDC205
Sunday 9 August 2009
1
• Scientific computing is concerned with
constructing mathematical models
and numerical solution techniques
and using computers to analyse and
solve scientific, social scientific and
engineering problems.
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2
Grading scheme
Weightage
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Internals
(quiz, lab)
25%
Midterm
30%
Final
45%
3
• Linear Systems
• Matrix Diagonalization
• Calculating eigenvalues/eigenvectors
• Random numbers/simulation
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History
• Traditionally known as numerical analysis
• Scientific computing as we know it started in the
1940s with the world war and cold war playing a
major role in pushing its development
• Codes for atomic bomb development
• Codes for projectile targeting
• Breaking ciphers
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Why Python?
• Python is simple to use
• extensive built-in run-time checks help to detect bugs
• being a very-high-level language, it has high-level data types
built in, such as flexible arrays and dictionaries that would
cost days to implement efficiently in C or Fortran
• Because of its general data types Python is applicable to a
large problem domain
Machine Language
Assembly
Sunday 9 August 2009
C
Fortran
Perl
Python
Lisp/Mathematica
MATLAB
x
∫e y
6
Why Python?
• Python is simple to use
• extensive built-in run-time checks help to detect bugs
• being a very-high-level language, it has high-level data types
built in, such as flexible arrays and dictionaries that would
cost days to implement efficiently in C or Fortran
• Because of its general data types Python is applicable to a
large problem domain
Machine Language
Assembly
Sunday 9 August 2009
C
Fortran
Perl
Python
Lisp/Mathematica
MATLAB
x
∫e y
6
Python vs MATLAB
• the Python programming language is more powerful
• the Python environment is completely open and made
for integration with external tools,
• a complete toolbox/module with lots of functions and
classes can be contained in a single file (in contrast to a
bunch of M-files),
• transferring functions as arguments to functions is
simpler,
• nested, heterogeneous data structures are simple to
construct and use,
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Python vs MATLAB
(cont.)
• object-oriented programming is more
convenient,
• interfacing C, C++, and Fortran code is
better supported and therefore simpler,
• scalar functions work with array
arguments to a larger extent (without
modifications of arithmetic operators),
• the source is free and runs on more
platforms.
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LINUX
• "Linux is user friendly, it's
just picky about its friends"
One OS to rule them all,
One OS to find them.
One OS to call them all,
And in salvation bind them.
In the bright land of Linux,
Where the hackers play.
(J. Scott Thayer, with apologies to J.R.R.T.)
The only "intuitive" interface is the nipple. After
that, it's all learned. --Bruce Ediger
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Python resources
• Beginners guide to Python
• http://wiki.python.org/moin/BeginnersGuide
• Python documentation
• http://www.python.org/doc/
• Python official website
• http://www.python.org/
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LINUX resources
• Basic LINUX commands
• http://www.linuxconfig.org/linuxcommands
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Hello World!
[farhat@webserver ~]$ python
Python 2.4.3 (#1, Dec 11 2006, 11:39:03)
[GCC 4.1.1 20061130 (Red Hat 4.1.1-43)] on linux2
Type "help", "copyright", "credits" or "license" for more
information.
>>> print "Hello world!"
Hello world!
>>>
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Hello World!
[farhat@webserver ~]$ python
Python 2.4.3 (#1, Dec 11 2006, 11:39:03)
[GCC 4.1.1 20061130 (Red Hat 4.1.1-43)] on linux2
Type "help", "copyright", "credits" or "license" for more
information.
>>> print "Hello world!"
Hello world!
>>>
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12
Hello World!
[farhat@webserver ~]$ python
Python 2.4.3 (#1, Dec 11 2006, 11:39:03)
[GCC 4.1.1 20061130 (Red Hat 4.1.1-43)] on linux2
Type "help", "copyright", "credits" or "license" for more
information.
>>> print "Hello world!"
Hello world!
>>>
[farhat@webserver ~]$ cat > helloworld.py
#!/usr/bin/python
print "Hello World!"
[farhat@webserver ~]$ python helloworld.py
Hello World!
[farhat@webserver ~]$ chmod 755 helloworld.py
[farhat@webserver ~]$ ./helloworld.py
Hello World!
[farhat@webserver ~]$
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If
[farhat@webserver ~]$ cat if.py
#!/usr/bin/python
print "Is the world flat?"
if True:
print "Be careful at the edge!"
[farhat@webserver ~]$ python if.py
Is the world flat?
Be careful at the edge!
[farhat@webserver ~]$
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For loop
>>> a = ['Mary', 'had', 'a', 'little', 'lamb']
>>> for i in range(len(a)):
... print i, a[i]
...
0 Mary
1 had
2a
3 little
4 lamb
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• Write a python program to output
Fibonnaci numbers upto 1000
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