<questionbank>

<question>

<topic>Plotting</topic>

<description>

Describe the plot produced by the following code

</description>

<time_limit>

30

</time_limit>

<code>

In []: x = linspace(0, 2*pi, 50)

In []: plot(x, cos(x), 'go')

</code>

<expected_answer>

Correct this question manually

</expected_answer>

</question>

<question>

<topic>Plotting</topic>

<description>

What ipython magic command do you use to obtain the lines of code you have already typed in the interpreter? What command do you use to save them?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

\%hist \%save

</expected_answer>

</question>

<question>

<topic>Plotting</topic>

<description>

How do you set the x and y labels of a plot to "x" and "sin(x)" ?

</description>

<time_limit>

60

</time_limit>

<expected_answer>

xlabel \( \" x \" \) ylabel \( \"sin\(x\)\" \)

xlabel \( \" x \" \) ylabel \( \'sin\(x\)\' \)

xlabel \( \' x \' \) ylabel \( \"sin\(x\)\" \)

xlabel \( \' x \' \) ylabel \( \'sin\(x\)\' \)

</expected_answer>

</question>

<question>

<topic>Plotting</topic>

<description>

How will you set the x and y axis limits so that the region of interest is in the rectangle (0, -1.5) and (2 pi, 1.5)?

</description>

<time_limit>

90

</time_limit>

<expected_answer>

xlim \( 0 , 2 \* pi \) [;,\n+] ylim \( -1\.5 , 1\.5 \)

</expected_answer>

</question>

<question>

<topic>Lists and Files</topic>

<description>

How do you combine two lists a and b to produce one list?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

a \+ b

</expected_answer>

</question>

<question>

<topic>Lists and Files</topic>

<description>

If a = [1, 2, 5, 9] how do you add 10 to the end of this list ?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

a\.append \( 10 \)

a = a \+ \[ 10 \]

a \+= \[ 10 \]

</expected_answer>

</question>

<question>

<topic>Lists and Files</topic>

<description>

Write the code to read a file "data.txt" and print each line of it?

</description>

<time_limit>

60

</time_limit>

<expected_answer>

correct this manually

</expected_answer>

</question>

<question>

<topic>For Loops</topic>

<description>

The following code snippet has an error/bug.

What is the error?

</description>

<code>

In []: l = [0.1, 0.2, 0.3, 0.4]

In []: t = [0.69, 0.90, 1.19, 1.30]

In []: tsq = []

In []: for time in t:

 ....:     tsq.append(time*time)

 ....:     plot(l, tsq)

</code>

<time_limit>

60

</time_limit>

<expected_answer>

plot

</expected_answer>

</question>

<question>

<topic>Strings</topic>

<description>

"Rossum, Guido, 42, 56, 34, 54" is a sample line from a Comma Separated Values (CSV) file

What code would you use to separate the line into fields?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

\.split \( " , " \)

\.split \( ' , ' \)

</expected_answer>

</question>

<question>

<topic>Lists and Files</topic>

<description>

If a = [1, 2, 5, 9] how do you find the length of this list?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

len \( a \)

</expected_answer>

</question>

<question>

<topic>Dictionaries and Piecharts</topic>

<description>

What is the output of the following code snippet

</description>

<code>

In [1]: d = {'a': 1,

             'b': 2

            }

In [2]: print d['c']

</code>

<time_limit>

30

</time_limit>

<expected_answer>

error

Error

ERROR

</expected_answer>

</question>

<question>

<topic>Dictionaries and Piecharts</topic>

<description>

Given the below dictionary, what command will you give to plot a pie-chart?

</description>

<code>

In []: sc = {'A': 10, 'B': 20, 'C': 70}

</code>

<time_limit>

60

</time_limit>

<expected_answer>

pie \( sc\.values \( \) \)

pie \( sc\.values \( \) , labels = sc\.keys \( \) \)

</expected_answer>

</question>

<question>

<topic>Statistics</topic>

<description>

Given the below marks, how will you calculate the mean?

</description>

<code>

In []: marks = [10, 20, 30, 50, 55, 75, 83] 

</code>

<time_limit>

30

</time_limit>

<expected_answer>

mean \( marks \)

sum \( marks \) \/ len \( marks \)

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

How will you convert the list marks to an array?

</description>

<code>

In []: marks = [10, 20, 30, 50, 55, 75, 83]

</code>

<time_limit>

30

</time_limit>

<expected_answer>

array \( marks \)

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

What is the value of a after executing this code.

</description>

<code>

In []: a = array([[1, 2],

                  [3, 4]])

In []: a[1,0] = 0

</code>

<time_limit>

60

</time_limit>

<expected_answer>

\[ \[ 1 , 2 \] , \[ 0 , 4 \] \]

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

What will be printed?

</description>

<code>

In []: x = array(([1,2,3,4],

                  [2,3,4,5]))

In []: x[-2][-3] = 4

In []: print x

</code>

<time_limit>

90

</time_limit>

<expected_answer>

array \( \( \[ 4 , 2 , 3 , 4 \] , \[ 2 , 3 , 4 , 5 \] \) \)

array \( \[ \[ 4 , 2 , 3 , 4 \] , \[ 2 , 3 , 4 , 5 \] \] \)

\[ \[ 4 , 2 , 3 , 4 \] , \[ 2 , 3 , 4 , 5 \] \]

\( \[ 4 , 2 , 3 , 4 \] , \[ 2 , 3 , 4 , 5 \] \)

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

If x = array([[1,2,3,4]]) How to change x to array([[1,2,0,4]]) ?

</description>

<time_limit>

60

</time_limit>

<expected_answer>

x\[ 0 \]\[ 2 \] = 0

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

x = array([[1,2,3,4],

           [3,4,2,5]])

How do you get the following slice of x ?

array([[2,3],

      [4,2]])

</description>

<time_limit>

60

</time_limit>

<expected_answer>

x\[ \: , 1 \: 3 \]

x\[ \: , 1 \: -1 \]

x\[ \: , -3 \: -1 \]

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

What is the output of x[::3,::3]

</description>

<code>

In []: x = array([[9,18,27],

                  [30,60,90],

                  [14,7,1]])

</code>

<time_limit>

30

</time_limit>

<expected_answer>

9

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

How do you get the transpose of this array?

</description>

<code>

In []: a = array([[1, 2],

                  [3, 4]])

</code>

<time_limit>

30

</time_limit>

<expected_answer>

a\.T

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

What does this produce?

</description>

<code>

In []: a = array([[1, 2],

                  [3, 4]])

In []: b = array([[1, 1],

                  [2, 2]])

In []: a*b

</code>

<time_limit>

45

</time_limit>

<expected_answer>

array \( \[ \[ 1 , 2 \] , \[ 6 , 8 \] \] \)

\[ \[ 1 , 2 \] , \[ 6 , 8 \] \]

</expected_answer>

</question>

<question>

<topic>Arrays and Matrices</topic>

<description>

What command do you use to find the inverse of a matrix and its eigenvalues?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

inv .* eigvals

</expected_answer>

</question>

<question>

<topic>Solving linear equations</topic>

<description>

Given a 4x4 matrix A and a 4-vector b , what command do you use to solve for the equation Ax = b ?

</description>

<time_limit>

45

</time_limit>

<expected_answer>

solve \( A , b \)

</expected_answer>

</question>

<question>

<topic>Finding roots</topic>

<description>

How do you calculate the roots of the polynomial, y = 1 + 6*x + 8*x^2 + x^3 

</description>

<time_limit>

45

</time_limit>

<expected_answer>

roots \( \[ 1 , 8 , 6 , 1 \] \)

</expected_answer>

</question>

<question>

<topic>Solving linear equations</topic>

<description>

Two arrays a and b are numerically almost equal, what command do you use to check if this is true?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

allclose \( a , b \)

allclose \( b , a \)

</expected_answer>

</question>

<question>

<topic>Basic Datatypes</topic>

<description>

What is the largest integer value that can be represented by Python?

</description>

<time_limit>

30

</time_limit>

<options>

No Limit

2**32

2**32 - 1

None of the above

</options>

<expected_answer>

No Limit

</expected_answer>

</question>

<question>

<topic>Basic Datatypes</topic>

<description>

What is the result of 17.0 / 2?

</description>

<time_limit>

15

</time_limit>

<expected_answer>

8.5

</expected_answer>

</question>

<question>

<topic>Basic Datatypes</topic>

<description>

Which of the following is not a type in Python?

</description>

<time_limit>

30

</time_limit>

<options>

int

float

char

string

</options>

<expected_answer>

char

</expected_answer>

</question>

<question>

<topic>Basic Datatypes</topic>

<description>

How do you create a complex number with real part 2 and imaginary part 0.5 ?

</description>

<time_limit>

30

</time_limit>

<expected_answer>

2 \+ 0\.5j

complex \( 2 , 0\.5 \)

</expected_answer>

</question>

<question>

<topic>Input and Output</topic>

<description>

What is the difference between print x and print x,

</description>

<time_limit>

30

</time_limit>

<expected_answer>

correct manually

</expected_answer>

</question>

<question>

<topic>Input and Output</topic>