Mathematical expressions with LaTeX in Matplotlib - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of LaTeX formatted plot title

What will be the title text shown on the plot after running this code?

Matplotlib

import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
plt.title(r'$y = x^2$')
plt.show()

A The plot title shows the text: y = x^2 with superscript formatting

B The plot title shows the text: y = x2 without superscript

C The plot title is empty with no text shown

D The plot title shows the raw string: $y = x^2$ without formatting

💡 Hint

Look at how LaTeX math expressions are wrapped with $ signs inside the raw string.

Using r'$y = x^2$' in plt.title tells matplotlib to render the text as a LaTeX math expression, so the superscript 2 appears correctly.

❓ data_output

intermediate

Number of tick labels with LaTeX formatting

How many x-axis tick labels will be shown after running this code?

Matplotlib

import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(0, 2, 5)
plt.plot(x, x**2)
plt.xticks(x, [f'$x_{{{int(i)}}}$' for i in x])
plt.show()

A 5 tick labels with LaTeX formatted subscripts x_0, x_0.5, x_1, x_1.5, x_2

B 5 tick labels with LaTeX formatted subscripts x_0, x_0, x_1, x_1, x_2

C 5 tick labels with LaTeX formatted subscripts x_0, x_1, x_2, x_3, x_4

D 5 tick labels with LaTeX formatted subscripts x_0, x_1, x_2, x_3, x_5

💡 Hint

Look carefully at how the labels are created using int(i) for each tick value.

The labels use int(i) which truncates decimals, so 0.5 and 1.5 become 0 and 1 respectively, causing repeated labels.

❓ visualization

advanced

Correct LaTeX rendering of integral expression in plot

Which option produces a plot with the title showing the integral \( \int_0^1 x^2 dx \) correctly formatted?

A plt.title(r'\int_0^1 x^2 dx')

B plt.title('$\int_0^1 x^2 dx$')

C plt.title('\int_0^1 x^2 dx')

D plt.title(r'$\int_0^1 x^2 dx$')

💡 Hint

Raw strings (r'') help avoid needing to double escape backslashes in LaTeX.

Option D uses a raw string with proper LaTeX math delimiters, so the integral renders correctly. Option D misses raw string so backslash escapes may fail. Options A and D miss math delimiters or have wrong escaping.

🔧 Debug

advanced

Identify the error in LaTeX expression for plot label

What error will this code produce when run?

Matplotlib

import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
plt.xlabel(r'$\frac{1}{2$')
plt.show()

A RuntimeError from matplotlib about invalid LaTeX syntax

B SyntaxError due to unmatched brace in LaTeX expression

C The label shows raw text $\frac{1}{2$ without formatting

D No error, label shows fraction 1/2 correctly

💡 Hint

Check if all braces in the LaTeX expression are properly closed.

The LaTeX expression has an opening brace '{' without a matching closing brace '}', causing matplotlib to raise a runtime error when rendering.

🚀 Application

expert

Create a plot with multiple LaTeX formatted annotations

Which code snippet correctly adds two LaTeX formatted annotations at points (1,1) and (2,4) on the plot?

A plt.annotate(r'y=1', (1,1)); plt.annotate(r'y=2^2', (2,4))

B plt.annotate('$y=1$', (1,1)); plt.annotate('$y=2^2$', (2,4))

C plt.annotate(r'$y=1$', (1,1)); plt.annotate(r'$y=2^2$', (2,4))

D plt.annotate('y=1', (1,1)); plt.annotate('y=2^2', (2,4))

💡 Hint

Raw strings with $ delimiters are needed for LaTeX math rendering in annotations.

Option C uses raw strings with $...$ which matplotlib interprets as LaTeX math, so annotations render correctly. Option C misses raw string so backslash escapes may fail. Options C and D miss $ delimiters so no math formatting.