Bubble charts concept in Matplotlib - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic bubble chart using matplotlib.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
sizes = [100, 200, 300, 400]
plt.scatter(x, y, s=[1])
plt.show()

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

Asizes

Bx

Cy

Dplt

Attempts:

3 left

💡 Hint

Common Mistakes

Using x or y instead of sizes for the bubble size parameter.

Forgetting to pass the sizes list to the s parameter.

The s parameter in plt.scatter sets the size of the bubbles. We use the sizes list to control bubble sizes.

2fill in blank

medium

Complete the code to add colors to the bubbles in the chart.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
sizes = [100, 200, 300, 400]
colors = ['red', 'blue', 'green', 'purple']
plt.scatter(x, y, s=sizes, c=[1])
plt.show()

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

Asizes

Bx

Ccolors

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Passing sizes or coordinates instead of colors to the c parameter.

Not passing any colors, resulting in default colors.

The c parameter in plt.scatter sets the colors of the bubbles. We use the colors list to assign colors.

3fill in blank

hard

Fix the error in the code to correctly display the bubble chart with labels.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
sizes = [100, 200, 300, 400]
labels = ['A', 'B', 'C', 'D']
plt.scatter(x, y, s=sizes)
for i, label in enumerate(labels):
    plt.text(x[i], y[i], [1])
plt.show()

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

Alabel

Blabels[i]

Clabels

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Using labels[i] instead of label inside the loop.

Using labels which is the whole list, not a single label.

Inside the loop, label holds the current label. Use it to place text on the chart.

4fill in blank

hard

Fill both blanks to create a bubble chart with transparency and a title.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
sizes = [100, 200, 300, 400]
plt.scatter(x, y, s=sizes, alpha=[1])
plt.[2]('My Bubble Chart')
plt.show()

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

A0.5

B0.8

Ctitle

Dxlabel

Attempts:

3 left

💡 Hint

Common Mistakes

Using xlabel instead of title for the plot title.

Setting alpha to a value greater than 1 or less than 0.

The alpha parameter controls transparency; 0.5 means 50% transparent. The title function adds a title to the plot.

5fill in blank

hard

Fill all three blanks to create a bubble chart with edge colors, a grid, and axis labels.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
sizes = [100, 200, 300, 400]
plt.scatter(x, y, s=sizes, edgecolors=[1])
plt.grid([2])
plt.xlabel([3])
plt.show()

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

A'black'

BTrue

C'X Axis'

D'none'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'none' for edgecolors which removes edges.

Passing False to plt.grid which hides the grid.

Not passing a string to plt.xlabel.

edgecolors='black' adds black edges to bubbles. plt.grid(True) shows grid lines. plt.xlabel('X Axis') labels the x-axis.

Practice

1. What does the size of bubbles represent in a bubble chart created with matplotlib?

easy

A. The color of the bubbles

B. A third data value representing magnitude or quantity

C. The x-axis position

D. The y-axis position

Solution

1. Step 1: Understand bubble chart data dimensions

   A bubble chart shows data points with x and y coordinates plus a size dimension.

2. Step 2: Identify what bubble size represents

   The size of each bubble encodes a third data value, like quantity or magnitude.

3. Final Answer:

   A third data value representing magnitude or quantity -> Option B

4. Quick Check:

   Bubble size = third data value [OK]

Hint: Bubble size shows extra data beyond x and y [OK]

Common Mistakes:

• Confusing size with color
• Thinking size is x or y position
• Ignoring the third data dimension

2. Which matplotlib function parameter controls the bubble sizes in a bubble chart?

easy

A. size

B. bubble_size

C. radius

D. s

Solution

1. Step 1: Recall plt.scatter parameters

   The plt.scatter function uses s to set bubble sizes.

2. Step 2: Confirm correct parameter name

   Other options like size or radius are not valid parameters for bubble size in plt.scatter.

3. Final Answer:

   s -> Option D

4. Quick Check:

   plt.scatter(x, y, s=...) sets bubble size [OK]

Hint: Use 's' parameter for bubble sizes in plt.scatter [OK]

Common Mistakes:

• Using 'size' instead of 's'
• Trying 'radius' which is invalid
• Confusing with color parameter

3. What will be the output of this code snippet?

import matplotlib.pyplot as plt
x = [1, 2, 3]
y = [4, 5, 6]
sizes = [100, 200, 300]
plt.scatter(x, y, s=sizes)
plt.show()

medium

A. A syntax error due to incorrect parameter

B. A scatter plot with all bubbles the same size

C. A scatter plot with three bubbles sized 100, 200, and 300 respectively

D. A scatter plot with bubbles sized 1, 2, and 3

Solution

1. Step 1: Analyze the code parameters

   The code uses plt.scatter with x, y coordinates and s=sizes where sizes are [100, 200, 300].

2. Step 2: Understand bubble size mapping

   Each bubble size corresponds to the values in the sizes list, so bubbles will have sizes 100, 200, and 300.

3. Final Answer:

   A scatter plot with three bubbles sized 100, 200, and 300 respectively -> Option C

4. Quick Check:

   Bubble sizes match 's' list values [OK]

Hint: Bubble sizes come from the 's' list values [OK]

Common Mistakes:

• Assuming all bubbles have same size
• Confusing sizes with x or y values
• Expecting syntax error incorrectly

4. Identify the error in this bubble chart code:

import matplotlib.pyplot as plt
x = [1, 2, 3]
y = [4, 5, 6]
sizes = [100, 200]
plt.scatter(x, y, s=sizes)
plt.show()

medium

A. The sizes list length does not match x and y lengths

B. The parameter 's' is misspelled

C. x and y must be strings, not lists

D. plt.scatter cannot plot more than two points

Solution

1. Step 1: Check lengths of x, y, and sizes

   x and y have 3 elements each, but sizes has only 2 elements.

2. Step 2: Understand size array length requirement

   The sizes array must match the number of points to assign size to each bubble.

3. Final Answer:

   The sizes list length does not match x and y lengths -> Option A

4. Quick Check:

   Sizes length must equal x and y length [OK]

Hint: Sizes array length must match x and y arrays [OK]

Common Mistakes:

• Ignoring size list length mismatch
• Thinking 's' parameter is misspelled
• Believing x and y must be strings

5. You want to create a bubble chart where bubble sizes represent sales volume, but sales data has zeros and very large values. Which approach is best to make the chart readable?

hard

A. Normalize sales data and apply a size scaling factor

B. Use raw sales values directly as sizes

C. Set all bubble sizes to a fixed constant

D. Use sales data as x-axis values instead

Solution

1. Step 1: Understand impact of raw sizes

   Using raw sales values with zeros and large numbers causes bubbles too small or too large, making chart unreadable.

2. Step 2: Normalize and scale sizes

   Normalizing sales data (e.g., min-max scaling) and applying a size factor keeps bubbles proportional and visible.

3. Step 3: Evaluate other options

   Fixed sizes lose data meaning; using sales as x-axis changes chart type and loses size info.

4. Final Answer:

   Normalize sales data and apply a size scaling factor -> Option A

5. Quick Check:

   Normalize and scale sizes for readability [OK]

Hint: Normalize and scale sizes to handle zeros and extremes [OK]

Common Mistakes:

• Using raw sizes causing unreadable bubbles
• Fixing all sizes losing data info
• Misusing sales data as axis instead of size