[Solved] Why does fcluster assign cluster labels starting from 1 instead of 0? — Ans: Because cluster labels represent group IDs starting at 1 by design. | SciPy

SciPy - Clustering and Distance

Why does fcluster assign cluster labels starting from 1 instead of 0?

ABecause cluster labels represent group IDs starting at 1 by design.

BBecause Python indexing always starts at 1.

CBecause 0 is reserved for noise points in clustering.

DBecause fcluster returns boolean arrays, not labels.

Step-by-Step Solution

Solution:

Step 1: Understand cluster label convention
fcluster assigns cluster IDs starting at 1 to represent cluster groups clearly.
Step 2: Clarify misconceptions
Python indexing starts at 0, but cluster labels are IDs, not indices. 0 is not reserved for noise here, and fcluster returns integer labels, not booleans.
Final Answer:
Because cluster labels represent group IDs starting at 1 by design. -> Option A
Quick Check:
Cluster labels start at 1 by design [OK]

Quick Trick: Cluster IDs start at 1, not zero [OK]

Common Mistakes:

Master "Clustering and Distance" in SciPy

9 interactive learning modes - each teaches the same concept differently

More SciPy Quizzes

Why does fcluster assign cluster labels starting from 1 instead of 0?