Skip to content

Alt text source: @allison_horst https://github.com/allisonhorst/penguins

You have been asked to support a team of researchers who have been collecting data about penguins in Antartica! The data is available in csv-Format as penguins.csv

Origin of this data : Data were collected and made available by Dr. Kristen Gorman and the Palmer Station, Antarctica LTER, a member of the Long Term Ecological Research Network.

The dataset consists of 5 columns.

ColumnDescription
culmen_length_mmculmen length (mm)
culmen_depth_mmculmen depth (mm)
flipper_length_mmflipper length (mm)
body_mass_gbody mass (g)
sexpenguin sex

Unfortunately, they have not been able to record the species of penguin, but they know that there are at least three species that are native to the region: Adelie, Chinstrap, and Gentoo. Your task is to apply your data science skills to help them identify groups in the dataset!

# Import required packages
import pandas as pd
import matplotlib.pyplot as plt
from sklearn.preprocessing import StandardScaler
from sklearn.cluster import KMeans

# Loading and examining the dataset
penguins_df = pd.read_csv('penguins.csv')
penguins_df.head()
penguins_df.info()

1 - Perform preprocessing steps on the dataset to create dummy variables

# Using get dummies method on the categorical feature
penguins_df = pd.get_dummies(penguins_df, drop_first=True)
penguins_df.head()
# Standardizing/scaling before clustering
scaler = StandardScaler()
X = scaler.fit_transform(penguins_df.drop(columns='sex_MALE'))
type(X)
print(X[:10])
df = pd.DataFrame(X, columns=penguins_df.drop(columns='sex_MALE').columns)
df.head()
penguins_preprocessed = pd.concat([df, penguins_df['sex_MALE']], axis=1)
penguins_preprocessed.head()

2 - Detect the optimal number of clusters for k-means clustering

# Perform Elbow analysis
ks = range(1,10)
inertias = []
for k in ks:
    model = KMeans(n_clusters=k, random_state=42)
    model.fit(penguins_preprocessed)
    inertias.append(model.inertia_)
print(inertias)
# Visualize the list of inertias
plt.plot(ks, inertias, '-o')
plt.xlabel('number of clusters, k')
plt.ylabel('inertia')
plt.title('Elbow Analysis/Method')
plt.xticks(ks)
plt.show()
# Optimal number of clusters - least number of clusters with lowest inertia
n_clusters = 4

3 - Run the k-means clustering algorithm