Subplot spacing adjustment in Matplotlib - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the vertical space between subplots?

Consider the following code that creates two subplots stacked vertically. What is the vertical space between the two plots after running this code?

Matplotlib

import matplotlib.pyplot as plt

fig, axs = plt.subplots(2, 1)
fig.subplots_adjust(hspace=0.5)
plt.show()

space = fig.subplotpars.hspace
print(space)

A 1.0

B 0.0

C 0.5

D 0.1

💡 Hint

Check the hspace parameter in subplots_adjust.

The hspace parameter controls the height (vertical) space between subplots. Setting hspace=0.5 means the vertical space is 0.5.

❓ data_output

intermediate

How many subplots fit without overlap?

Given the code below, how many subplots will fit in the figure without overlapping when wspace=0.2 and hspace=0.2?

Matplotlib

import matplotlib.pyplot as plt

fig, axs = plt.subplots(3, 3)
fig.subplots_adjust(wspace=0.2, hspace=0.2)
plt.show()

rows = len(axs)
cols = len(axs[0])
print(rows * cols)

A 6

B 0

C 3

D 9

💡 Hint

Count the total number of subplots created by plt.subplots(3, 3).

The code creates a 3 by 3 grid of subplots, so there are 9 subplots total. The spacing parameters do not reduce the number of subplots.

❓ visualization

advanced

Which option produces the tightest subplot layout?

Which code snippet produces the tightest layout with minimal space between subplots?

A fig.subplots_adjust(left=0.1, right=0.9, top=0.9, bottom=0.1, wspace=0.05, hspace=0.05)

B fig.subplots_adjust(left=0.2, right=0.8, top=0.8, bottom=0.2, wspace=0.5, hspace=0.5)

C fig.subplots_adjust(left=0.0, right=1.0, top=1.0, bottom=0.0, wspace=1.0, hspace=1.0)

D fig.subplots_adjust(left=0.3, right=0.7, top=0.7, bottom=0.3, wspace=0.3, hspace=0.3)

💡 Hint

Smaller wspace and hspace values mean less space between subplots.

Option A uses the smallest wspace and hspace values (0.05), and the margins are reasonably tight, so it produces the tightest layout.

🔧 Debug

advanced

Why does this subplot spacing code raise an error?

What error does the following code raise and why?

import matplotlib.pyplot as plt
fig, axs = plt.subplots(2, 2)
fig.subplots_adjust(wspace=-0.1, hspace=0.2)
plt.show()

A TypeError: wspace must be a float

B ValueError: wspace must be >= 0

C No error, plots display normally

D AttributeError: subplots_adjust has no attribute wspace

💡 Hint

Check the allowed range for wspace values.

The wspace parameter cannot be negative. Setting wspace=-0.1 raises a ValueError.

🚀 Application

expert

Adjust subplot spacing to avoid label overlap

You have a 2x2 grid of subplots with long x-axis labels that overlap. Which code snippet best adjusts spacing to avoid overlap while keeping the figure compact?

Matplotlib

import matplotlib.pyplot as plt
fig, axs = plt.subplots(2, 2)
for ax in axs.flat:
    ax.set_xlabel('Long x-axis label example')
fig.subplots_adjust(PLACEHOLDER)
plt.show()

A left=0.1, right=0.9, top=0.9, bottom=0.3, wspace=0.3, hspace=0.4

B left=0.2, right=0.8, top=0.8, bottom=0.1, wspace=0.1, hspace=0.1

C left=0.05, right=0.95, top=0.95, bottom=0.05, wspace=0.05, hspace=0.05

D left=0.3, right=0.7, top=0.7, bottom=0.5, wspace=0.5, hspace=0.5

💡 Hint

Increasing bottom margin and vertical space helps avoid x-label overlap.

Option A increases the bottom margin and vertical spacing to prevent label overlap while keeping the figure compact. Other options either have too small bottom margin or too large spacing.

Practice

1. What does the plt.subplots_adjust() function do in matplotlib?

easy

A. It changes the space between subplots in a figure.

B. It creates new subplots in a figure.

C. It saves the figure to a file.

D. It changes the color of the plot lines.

Solution

1. Step 1: Understand the purpose of plt.subplots_adjust()

   This function is used to control the spacing between subplots in a matplotlib figure.

2. Step 2: Compare options

   Only It changes the space between subplots in a figure. correctly describes adjusting space between subplots. Other options describe different functions.

3. Final Answer:

   It changes the space between subplots in a figure. -> Option A

4. Quick Check:

   Subplot spacing adjustment = plt.subplots_adjust() [OK]

Hint: Remember: adjust spacing, not create or save plots [OK]

Common Mistakes:

• Confusing subplot creation with spacing adjustment
• Thinking it saves the figure
• Mixing it with styling functions

2. Which of the following is the correct syntax to increase horizontal space between subplots using plt.subplots_adjust()?

easy

A. plt.subplots_adjust(hspace=0.5)

B. plt.subplots_adjust(space=0.5)

C. plt.subplots_adjust(wspace=0.5)

D. plt.subplots_adjust(widthspace=0.5)

Solution

1. Step 1: Identify parameter for horizontal spacing

   The parameter wspace controls horizontal space between subplots.

2. Step 2: Check syntax correctness

   plt.subplots_adjust(wspace=0.5) uses wspace=0.5, which is correct. Other options use incorrect or non-existent parameters.

3. Final Answer:

   plt.subplots_adjust(wspace=0.5) -> Option C

4. Quick Check:

   wspace adjusts horizontal space [OK]

Hint: Use wspace for width (horizontal), hspace for height (vertical) [OK]

Common Mistakes:

• Using hspace instead of wspace for horizontal spacing
• Using wrong parameter names like space or widthspace
• Syntax errors in function call

3. What will be the effect of this code on subplot spacing?

import matplotlib.pyplot as plt
fig, axs = plt.subplots(1, 2)
plt.subplots_adjust(wspace=1.0)
plt.show()

medium

A. Subplots will have increased horizontal space between them.

B. Subplots will be very close horizontally with almost no space.

C. Subplots will overlap each other.

D. Subplots will have increased vertical space between them.

Solution

1. Step 1: Understand wspace=1.0 effect

   Setting wspace to 1.0 increases horizontal space between subplots significantly.

2. Step 2: Analyze code behavior

   Since there are 2 subplots side by side, they will be spaced apart horizontally, not vertically.

3. Final Answer:

   Subplots will have increased horizontal space between them. -> Option A

4. Quick Check:

   wspace=1.0 means more horizontal space [OK]

Hint: wspace controls horizontal gap size between subplots [OK]

Common Mistakes:

• Confusing wspace with hspace
• Expecting subplots to overlap
• Thinking spacing affects vertical gap

4. Identify the error in this code that tries to adjust subplot spacing:

import matplotlib.pyplot as plt
fig, axs = plt.subplots(2, 1)
plt.subplots_adjust(wspace=0.3, hspace=0.5)
plt.show()

medium

A. Using hspace with vertical subplots is invalid.

B. Using wspace when subplots are stacked vertically.

C. Incorrect number of subplots created.

D. Missing plt.show() call.

Solution

1. Step 1: Analyze subplot layout

   The code creates 2 subplots stacked vertically (2 rows, 1 column).

2. Step 2: Check spacing parameters

   wspace controls horizontal spacing, which is irrelevant here because subplots are vertical. Only hspace affects vertical spacing.

3. Final Answer:

   Using wspace when subplots are stacked vertically. -> Option B

4. Quick Check:

   wspace for horizontal, not vertical spacing [OK]

Hint: Match wspace to horizontal, hspace to vertical layout [OK]

Common Mistakes:

• Using wspace for vertical subplot spacing
• Ignoring subplot grid shape
• Assuming hspace is invalid for vertical layout

5. You have a 2x2 grid of subplots with overlapping x-axis labels. Which plt.subplots_adjust() call best reduces overlap by increasing vertical space and adding some horizontal space?

hard

A. plt.subplots_adjust(wspace=1.5, hspace=0.0)

B. plt.subplots_adjust(wspace=0.0, hspace=0.0)

C. plt.subplots_adjust(wspace=0.0, hspace=1.5)

D. plt.subplots_adjust(wspace=0.4, hspace=0.6)

Solution

1. Step 1: Understand the problem of overlapping x-axis labels

   Overlapping x-axis labels usually happen vertically between rows, so increasing vertical space (hspace) helps.

2. Step 2: Consider horizontal space

   Adding some horizontal space (wspace) also improves readability between columns.

3. Step 3: Evaluate options

   plt.subplots_adjust(wspace=0.4, hspace=0.6) increases both wspace and hspace moderately, which best reduces overlap without wasting space.

4. Final Answer:

   plt.subplots_adjust(wspace=0.4, hspace=0.6) -> Option D

5. Quick Check:

   Increase hspace and wspace moderately to reduce overlap [OK]

Hint: Increase hspace for vertical gaps, wspace for horizontal gaps [OK]

Common Mistakes:

• Setting spacing to zero causing overlap
• Increasing only one spacing dimension
• Using too large spacing causing wasted space