np.linspace() for evenly spaced arrays in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an array of 5 numbers evenly spaced between 0 and 10.

NumPy

import numpy as np
arr = np.linspace(0, 10, [1])
print(arr)

Drag options to blanks, or click blank then click option'

A5

B10

C3

D7

Attempts:

3 left

💡 Hint

Common Mistakes

Using 10 instead of 5 creates more points than needed.

Forgetting the third argument defaults to 50 points.

The third argument in np.linspace() specifies how many numbers to generate. Here, 5 numbers between 0 and 10 are created.

2fill in blank

medium

Complete the code to create 4 numbers evenly spaced between 1 and 2.

NumPy

import numpy as np
arr = np.linspace(1, [1], 4)
print(arr)

Drag options to blanks, or click blank then click option'

A2

B4

C3

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 or 4 as the end value changes the range incorrectly.

Confusing the number of points with the end value.

The second argument is the end value. Here, 4 numbers between 1 and 2 are created.

3fill in blank

hard

Fix the error in the code to generate 6 numbers from 0 to 5.

NumPy

import numpy as np
arr = np.linspace(0, 5, [1])
print(arr)

Drag options to blanks, or click blank then click option'

A4

B5

C6

D7

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 generates only five numbers, missing one point.

Using 7 generates too many points.

The third argument must be 6 to get six numbers including both 0 and 5.

4fill in blank

hard

Fill both blanks to create an array of 7 numbers from 10 to 20.

NumPy

import numpy as np
arr = np.linspace([1], [2], 7)
print(arr)

Drag options to blanks, or click blank then click option'

A10

B15

C20

D25

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping start and end values.

Using 15 or 25 changes the range incorrectly.

The first blank is the start (10), the second blank is the end (20), and 7 numbers are generated between them.

5fill in blank

hard

Fill all three blanks to create a dictionary with keys as numbers from 1 to 5 and values as their squares using np.linspace().

NumPy

import numpy as np
numbers = np.linspace([1], [2], [3])
squares = {int(num): int(num)**2 for num in numbers}
print(squares)

Drag options to blanks, or click blank then click option'

A1

B5

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using 10 as the end value changes the range incorrectly.

Using fewer or more than 5 points changes the keys.

The numbers start at 1, end at 5, and there are 5 points to get integers 1 to 5. The dictionary comprehension creates squares.

Practice

1. What does the np.linspace(start, stop, num) function do in NumPy?

easy

A. Generates integers from start to stop with step size num.

B. Generates random numbers between start and stop.

C. Generates num evenly spaced numbers between start and stop inclusive.

D. Generates a sequence of numbers starting at start with length num.

Solution

1. Step 1: Understand the function purpose

   np.linspace creates numbers evenly spaced between two points.

2. Step 2: Analyze parameters

   The parameters start, stop, and num define the range and count of numbers.

3. Final Answer:

   Generates num evenly spaced numbers between start and stop inclusive. -> Option C

4. Quick Check:

   np.linspace = evenly spaced numbers [OK]

Hint: Remember: linspace means linear spacing between start and stop [OK]

Common Mistakes:

• Confusing linspace with random number generation
• Thinking it generates integers only
• Assuming it excludes the stop value by default

2. Which of the following is the correct syntax to create 5 evenly spaced numbers from 0 to 10 using np.linspace?

easy

A. np.linspace(5, 0, 10)

B. np.linspace(0, 10, 5)

C. np.linspace(start=0, stop=10)

D. np.linspace(0, 10, step=5)

Solution

1. Step 1: Check parameter order and count

   np.linspace requires start, stop, and num (number of points).

2. Step 2: Validate each option

   np.linspace(0, 10, 5) correctly uses start=0, stop=10, and num=5. np.linspace(0, 10, step=5) wrongly uses step which is invalid. np.linspace(start=0, stop=10) misses num. np.linspace(5, 0, 10) reverses start and stop and uses wrong count.

3. Final Answer:

   np.linspace(0, 10, 5) -> Option B

4. Quick Check:

   Correct syntax includes start, stop, and number [OK]

Hint: Use (start, stop, num) order; no step parameter [OK]

Common Mistakes:

• Using step instead of num
• Omitting the number of points
• Reversing start and stop unintentionally

3. What is the output of the following code?

import numpy as np
arr = np.linspace(2, 6, 3)
print(arr)

medium

A. [2. 6. 10.]

B. [2. 3. 4.]

C. [2. 3.5 5.]

D. [2. 4. 6.]

Solution

1. Step 1: Understand parameters

   The code creates 3 numbers evenly spaced from 2 to 6 inclusive.

2. Step 2: Calculate spacing and values

   Spacing = (6 - 2) / (3 - 1) = 2. Values: 2, 4, 6.

3. Final Answer:

   [2. 4. 6.] -> Option D

4. Quick Check:

   3 points from 2 to 6 spaced by 2 [OK]

Hint: Divide range by (num-1) to find step size [OK]

Common Mistakes:

• Assuming step size is 1
• Confusing number of points with step size
• Forgetting that stop is included by default

4. Which of the following statements is correct about this code snippet:

import numpy as np
arr = np.linspace(1, 5)
print(arr)

medium

A. Missing the number of points to generate.

B. Start value cannot be less than stop value.

C. np.linspace requires integer inputs only.

D. The print statement is incorrect.

Solution

1. Step 1: Check function parameters

   np.linspace requires start and stop, with num optional (defaults to 50).

2. Step 2: Examine the code

   The code omits num, so it uses the default of 50 points.

3. Step 3: Evaluate options

   A: False, start can be less than stop. B: Incorrect, the number of points is not missing, it defaults to 50. C: False, floats are allowed. D: False, print is correct.

4. Final Answer:

   np.linspace uses a default number of points (50) if num is omitted, so no error occurs. -> Option A

5. Quick Check:

   Default num=50 if omitted in linspace [OK]

Hint: Remember num defaults to 50 if not given [OK]

Common Mistakes:

• Thinking num is mandatory
• Assuming start must be greater than stop
• Believing only integers allowed

5. You want to create a smooth curve for plotting a sine wave between 0 and 2π. Which np.linspace call is best to generate 100 points including 0 and 2π?

hard

A. np.linspace(0, 2*np.pi, 100, endpoint=True)

B. np.linspace(0, 2*np.pi, 100, endpoint=False)

C. np.linspace(0, 2*np.pi, 99, endpoint=True)

D. np.linspace(0, 2*np.pi, 101, endpoint=False)

Solution

1. Step 1: Understand plotting needs

   For smooth plotting, include both start (0) and stop (2π) points with enough samples.

2. Step 2: Analyze options

   np.linspace(0, 2*np.pi, 100, endpoint=True) generates 100 points including 2π (endpoint=True). np.linspace(0, 2*np.pi, 100, endpoint=False) excludes 2π, which may cause plot to miss endpoint. Options A, B, and D have wrong number of points or exclude endpoint.

3. Final Answer:

   np.linspace(0, 2*np.pi, 100, endpoint=True) -> Option A

4. Quick Check:

   Include endpoint for full range in plotting [OK]

Hint: Use endpoint=True to include last point in plots [OK]

Common Mistakes:

• Excluding endpoint causing incomplete plots
• Using too few points for smooth curves
• Confusing number of points with step size