Q&A 39 How do you visualize the relationship between two numerical variables using a scatter plot?

39.1 Explanation

A scatter plot displays the relationship between two continuous variables. Each point represents an observation, with its position defined by the values of two numeric features.

• Helps detect linear or nonlinear trends
• Reveals outliers or clusters
• Useful for checking correlation

This is often a starting point for exploring predictor-response relationships in regression or feature selection tasks.

39.2 Python Code

import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt

# Load the iris dataset
df = pd.read_csv("data/iris.csv")

# Basic scatter plot: sepal_length vs petal_length
plt.figure(figsize=(6, 4))
sns.scatterplot(data=df, x="sepal_length", y="petal_length")
plt.title("Scatter Plot of Sepal Length vs Petal Length")
plt.tight_layout()
plt.show()

39.3 R Code

library(ggplot2)
library(readr)

# Load the dataset
df <- read_csv("data/iris.csv")

# Basic scatter plot: sepal_length vs petal_length
ggplot(df, aes(x = sepal_length, y = petal_length)) +
  geom_point() +
  labs(title = "Scatter Plot of Sepal Length vs Petal Length") +
  theme_minimal()