Difference between revisions of "Python"

Revision as of 11:15, 11 June 2015

IIT Bombay is leading the effort to popularise Python for Scientific Computing in India. This is part of the Free and Open source Software for Science and Engineering Education (http://fossee.in) project, supported by the National Mission on Education through ICT of MHRD (http://spoken-tutorial.org/NMEICT-Intro).

IIT Bombay is using Spoken Tutorials (http://spoken-tutorial.org) to create learning material for FOSS. This is the main page for the organisation of the scripts required for Standard two day workshop we conduct on "Python for Scientific Computing" spoken tutorials.

Module 1: Basic Plotting

Getting started with ipython

invoking ipython
if there's a problem, pre-requisites are not met.

getting out

explain the prompt

typing commands
- 1+2
  - careful wording to differentiate from print
- print 1+2
- history (up, down arrows)
- backspace, delete key
- tab completion
  - ab
  - a
  - rou
  - ro
  - r

abs?, round?

handling typing errors
- round(2.48,
  - close it
  - use ^C

Using the plot command interactively

ipython -pylab
- pylab brings in the libraries necessary for Scientific Computing.

linspace,

len

clf

plot

using the plot ui

Embellishing a plot

Title

Label

line width, color, style

annotations

Saving plots

basic savefig

png, pdf, ps, eps, svg

going to OS and looking at the file

Multiple plots

overlays
- linspace
  - give one with very few points, more points
  - show smoothness of the curve

legend

figure 1, figure2

subplots

Additional features of IPython

%save, %history, %run

Module 2: Plotting Experimental Data

loading data from files

loadtxt with unpack=True
- primes.list (one col)
- pendulum.txt (two col)

Plotting the data

plot L vs. T²
- using square function

problem with 3 cols
- 3rd column is error
- error bar

Other types of plots

scatter

pie chart

bar chart

log

illustration of other plots, matplotlib help

Module 3: using Sage

Getting started with sage notebook

about sage
- …

starting the notebook server

using the UI
- typesetting & print
- selecting language
  - sage
  - LaTeX
  - python
- help
  - sum(<tab>
  - ?

Getting started with symbolics

symbolic expressions
- built-in constants & functions
- algebraic expressions,
- series
- integration, differentiation
- matrices

symbolic functions
- defining

simplification

finding roots & factors

substituting expressions

output formats

Using Sage

ABCD
- Degree
  - RBT - U

Calculus
- limits
- differentiation
- integration
  - indefinite
  - definite
- piece-wise functions
- differential equations
- maxima, minima

Linear Algebra
- Vectors and Matrices
  - constructions
- Vector Operations
  - linear combination
  - dot
  - cross
  - pairwise
- Matrix Operations
  - linear combination
  - matrix multiplication
  - inverse
  - transpose
  - adjoint
  - rank
  - determinant
  - trace
  - norm
- Solving equations
- Eigenvalues, eigenvectors

Graph Theory

Number Theory

Using sage to teach

@interact

2D, 3D graphics

Graph Theory

Share, Publish

print

Module 4: Handling Large Data Files

Getting started with lists

empty

filled lists
- heterogenity

accessing

len

append elements

del (+ remove)

Getting started with for

blocks in python
- (indentation)

blocks in ipython
- … prompt
- hitting enter

for with a list

range function

Getting started with strings

strings
- single, double, triple quoted

accessing elements

show immutability

tell that there are methods for manipulation

Getting started with files

show file object

read the file with read

closing the file

for line in file:

print a line

append the lines to a list

Parsing data

explain what is parsing

strip (with strings)

split (with strings)
- with delimiters
  - specify space as delimiter

datatype conversion

reading from files
- do the same problem done with loadtxt (for pendulum)
- basic parse sslc text

Statistics

mean
- summing

median

std

Module 5: Arrays and Matrices

Getting started with arrays

why arrays
- speed - simply say
- array level operations

creating arrays
- direct data
- list conversion
- homogeneous
- builtins - identitiy, zeros,

array operations
- + - * /

Accessing parts of arrays

accessing individual elements

changing individual elements

slicing, striding

image manipulation

Matrices

(Scripts)

creating matrices
- direct data
- list conversion
- builtins - identitiy, zeros,

matrix operations
- + - * /
- dot
- inv
- det
- eig
- norm
- svd

Least square fit

show pendulum
- use loadtxt

lstsq

Module 6: Python Language: Basics

Basic datatypes & operators

int
- L, long

float
- repr, str

complex

boolean

conversion functions

sequence datatypes & mutability
- list available sequence datatypes
  - string
  - list
  - tuple
- mutability
- conversion
- common stuff
  - len
  - in
  - max, min, sum, sorted, reversed
  - accessing individual elements
  - slicing, striding

I/O

Input Output in Python

Conditionals

if, elif, else

pass

Loops