Exercises (session 5)

Fossee

Description

ExercisesFOSSEEDepartment of Aerospace EngineeringIIT BombaySciPy 2010, Introductory tutorialsDay 1, Session 5FOSSEE (IIT Bombay) Exercises 1 / 16Problem 1Example codel = []t = []for line in open(’pendulum.txt’):point = line.split()l.append(float(point[0]))t.append(float(point[1]))plot(l, t, ’.’)Problem StatementTweak above code to plot ...

Sujets

• Python
• Tutoriel
• Calcul (mathématiques)

Informations

• Publié par: mtoledan
• Publié le: 27 juin 2011
• Nombre de lectures: 159
• Langue: English

Extrait

OFSSEEI(TIBom

Exercises

FOSSEE

Department of Aerospace Engineering IIT Bombay

SciPy 2010, Introductory tutorials Day 1, Session 5

ab)yxEreicess1/16

Problem 1

Example code

l = [] t = [] for line in open( ’pendulum.txt’ ): point = line.split() l.append(float(point[0])) t.append(float(point[1])) plot(l, t, ’.’ )

Problem Statement Tweak above code to plot data in file pos.txt .

FOSSEE(IITBombay)Exercises2/61

Problem 1 cont...

FO

Label both the axes. What kind of motion is this? Title the graph accordingly. Annotate the position where vertical velocity is zero.

SSEEI(TIoBbmya)Exercises3/16

Problem 2

Plot points given x and y coordinates

In []: x = [3, 2, -2, 3] In []: y = [1, -3, 4, 1] In []: plot(x, y)

Line can be plotted using arrays of coordinates.

Problem statement Write a Program that plots a regular n-gon(Let n = 5).

FOSSEE(IITBombay)xEercises4/61

Problem 2

Plot points given x and y coordinates

In []: x = [3, 2, 2, 3] - In []: y = [1, -3, 4, 1] In []: plot(x, y)

Line can be plotted using arrays of coordinates.

Problem statement Write a Program that plots a regular n-gon(Let n = 5).

FOSSEE(IIToBbmya)xEercises4/16

Problem

OFSSEEI(TIoBmbay)

3

Exercises

Damped Oscillation

In []: t = linspace(0, 4*pi) In []: plot(t, exp(t/10)*sin(t))

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Problem 3 cont...

Create a sequence of images in which the damped oscillator( e − t / 10 sin ( t ) ) slowly evolves over time t .

Hint

savefig( ’plot’ +str(i)+ ’.png’ )

OFSSEE(IITBombay)Exercises

#i

is

some

int

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Problem 4

In []: In []: Out[]: In []: In []:

x = imread( ’smoothing.gif’ ) x.shape (256, 256) imshow(x,cmap=cm.gray) colorbar()

Replace each pixel with mean of neighboring pixels

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FOSSEE

(IIT

Bombay)

Exercises

8

/

16

Problem 4: Approach

For y being resultant image:

y[1,

1]

Hint: Use array

=

x[0, 1]/4 + + x[2, 1]/4

Slicing.

FOSSEE (IIT Bombay)

Exercises

x[1, 0]/4 + x[1, 2]/4

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Solution

In In

In

FO

[]: []:

[]:

SSEE(IITB

y = zeros_like(x) y[1:-1,1:-1] = x[:-2,1:-1]/4 + x[2:,1:-1]/4 + x[1:-1,2:]/4 + x[1:-1,:-2]/4 imshow(y,cmap=cm.gray)

mobay)xEercises01/61