Figure size for publication in Matplotlib - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the figsize parameter control in matplotlib?

The figsize parameter sets the width and height of a figure in inches. It controls the size of the plot you create.

beginner

Why is setting the correct figure size important for publication?

Correct figure size ensures the plot fits well in the publication layout, maintains readability, and preserves details without distortion.

beginner

How do you set a figure size of 6 inches wide and 4 inches tall in matplotlib?

Use plt.figure(figsize=(6, 4)) before plotting to set the figure size to 6 inches wide and 4 inches tall.

beginner

What unit does matplotlib use for figure size dimensions?

Matplotlib uses inches as the unit for figure size dimensions.

intermediate

How can you check the current size of a matplotlib figure?

You can check the size by calling fig.get_size_inches() on the figure object.

What does figsize=(8, 6) mean in matplotlib?

A Figure width is 8 inches and height is 6 inches

B Figure width is 8 pixels and height is 6 pixels

C Figure width is 6 inches and height is 8 inches

D Figure width and height are both 8 inches

The figsize tuple sets width first, then height, both in inches.

Why might you want to set a smaller figure size for publication?

A To make the plot fit better in a column or page

B To reduce the number of colors used

C To increase the font size automatically

D To change the plot type

Smaller figure sizes help the plot fit well in the publication layout.

Which matplotlib function is used to create a figure with a specific size?

A plt.set_size(width, height)

B plt.plot(figsize=(width, height))

C plt.size(width, height)

D plt.figure(figsize=(width, height))

plt.figure() creates a figure and figsize sets its size.

What unit is NOT used by matplotlib for figure size?

A Inches

B Pixels

C Centimeters

D Points

Matplotlib uses inches, not centimeters, for figure size.

How can you retrieve the size of an existing matplotlib figure?

A plt.get_figsize()

B fig.get_size_inches()

C fig.size()

D plt.figure_size()

The get_size_inches() method returns the figure size in inches.

Explain how to set and check the figure size in matplotlib for a publication-ready plot.

Think about how inches relate to the final printed or displayed plot.

Why is it important to choose the right figure size when preparing plots for publication?

Consider how a plot looks on a printed page or in a journal.

Practice

1. What does the figsize parameter control in a matplotlib figure?

easy

A. The font size of the labels

B. The width and height of the figure in inches

C. The color of the figure background

D. The style of the plot lines

Solution

1. Step 1: Understand the role of figsize

   The figsize parameter sets the size of the entire figure in inches, controlling width and height.

2. Step 2: Differentiate from other parameters

   Other parameters like color or font size do not affect figure size but appearance details.

3. Final Answer:

   The width and height of the figure in inches -> Option B

4. Quick Check:

   Figure size = width and height in inches [OK]

Hint: Remember figsize sets width and height in inches [OK]

Common Mistakes:

• Confusing figsize with color or font size
• Thinking figsize controls plot line style
• Assuming figsize is in pixels

2. Which of the following is the correct way to set a figure size of 8 inches wide and 4 inches tall in matplotlib?

easy

A. plt.figure(size=[8, 4])

B. plt.figure(size=(8, 4))

C. plt.figure(width=8, height=4)

D. plt.figure(figsize=(8, 4))

Solution

1. Step 1: Recall correct parameter name and type

   The parameter to set figure size is figsize and it expects a tuple (width, height).

2. Step 2: Check syntax correctness

   plt.figure(figsize=(8, 4)) uses figsize=(8, 4) which is correct syntax. Using size causes TypeError (unexpected keyword). Using width=8, height=4 also causes TypeError (no such parameters).

3. Final Answer:

   plt.figure(figsize=(8, 4)) -> Option D

4. Quick Check:

   Use figsize=(width, height) tuple [OK]

Hint: Use figsize=(width, height) tuple in plt.figure() [OK]

Common Mistakes:

• Using 'size' instead of 'figsize'
• Using separate width and height parameters
• Forgetting parentheses around figsize values

3. What will be the size of the figure in inches after running this code?

import matplotlib.pyplot as plt
plt.figure(figsize=(6, 3))
plt.plot([1, 2, 3], [4, 5, 6])
plt.show()

medium

A. 6 inches wide and 3 inches tall

B. 3 inches wide and 6 inches tall

C. Default size (usually 6.4 x 4.8 inches)

D. Cannot determine without dpi

Solution

1. Step 1: Identify figsize parameter values

   The code sets figsize=(6, 3), which means width=6 inches and height=3 inches.

2. Step 2: Understand effect on figure size

   This directly sets the figure size regardless of dpi, so the figure will be 6 inches wide and 3 inches tall.

3. Final Answer:

   6 inches wide and 3 inches tall -> Option A

4. Quick Check:

   figsize=(6, 3) means width=6, height=3 inches [OK]

Hint: figsize=(width, height) sets exact figure size in inches [OK]

Common Mistakes:

• Swapping width and height values
• Thinking dpi affects figsize dimensions
• Assuming default size if figsize is set

4. Identify the error in this code that tries to set figure size:

import matplotlib.pyplot as plt
plt.figure(figsize=8, 4)
plt.plot([1, 2], [3, 4])
plt.show()

medium

A. No error, code runs fine

B. plt.plot syntax is incorrect

C. figsize should be a tuple, not two separate arguments

D. plt.show() is missing parentheses

Solution

1. Step 1: Check figsize parameter usage

   The code uses figsize=8, 4 which passes two separate arguments instead of a single tuple.

2. Step 2: Understand correct figsize syntax

   Correct syntax requires a tuple: figsize=(8, 4). Without parentheses, it causes a TypeError.

3. Final Answer:

   figsize should be a tuple, not two separate arguments -> Option C

4. Quick Check:

   figsize=(width, height) needs parentheses [OK]

Hint: Always use parentheses for figsize tuple [OK]

Common Mistakes:

• Passing figsize values without parentheses
• Confusing plt.plot syntax errors
• Forgetting plt.show() parentheses (not the case here)

5. You want to create a publication-ready plot with a width of 7 inches and height of 5 inches. You also want to save it as a PNG file with 300 dpi resolution. Which code snippet correctly sets the figure size and saves the plot?

hard

A. plt.figure(figsize=(7, 5))
plt.plot(data)
plt.savefig('plot.png', dpi=300)

B. plt.figure(size=(7, 5))
plt.plot(data)
plt.savefig('plot.png', dpi=300)

C. plt.figure(figsize=[7, 5])
plt.plot(data)
plt.savefig('plot.png')

D. plt.figure(figsize=(7, 5))
plt.plot(data)
plt.save('plot.png', dpi=300)

Solution

1. Step 1: Set figure size correctly

   Use figsize=(7, 5) tuple in plt.figure() to set width and height in inches.

2. Step 2: Save figure with correct dpi and function

   Use plt.savefig('plot.png', dpi=300) to save with 300 dpi resolution. plt.figure(size=(7, 5)) plt.plot(data) plt.savefig('plot.png', dpi=300) uses wrong parameter size. plt.figure(figsize=[7, 5]) plt.plot(data) plt.savefig('plot.png') misses dpi. plt.figure(figsize=(7, 5)) plt.plot(data) plt.save('plot.png', dpi=300) uses wrong function plt.save.

3. Final Answer:

   plt.figure(figsize=(7, 5)) plt.plot(data) plt.savefig('plot.png', dpi=300) -> Option A

4. Quick Check:

   figsize tuple + savefig with dpi=300 [OK]

Hint: Use figsize tuple and savefig with dpi for publication [OK]

Common Mistakes:

• Using 'size' instead of 'figsize'
• Forgetting dpi in savefig for quality
• Using plt.save instead of plt.savefig