Hadamard matrix
Matriz de Hadamard
- Date
- 1893 · confidence medium
- Place
- Bordeaux, France
- Credited to
- Jacques Hadamard
- Field
- Knowledge & symbols
⚠️ Disputed: the sources disagree.
What was discovered
A square matrix whose entries are +1 or -1 and whose rows are mutually orthogonal, giving it the maximum possible volume among matrices with entries bounded by 1. It gives rise to error-correcting codes and is used in balanced repeated replication statistical techniques.
James Joseph Sylvester had already constructed matrices of this type in 1867; Jacques Hadamard formally studied them in 1893 and bounded their maximal determinant, hence the usual name.
What it led to
- Hadamard codes, later generalised into Reed-Muller codes
- balanced repeated replication (BRR) statistical techniques
- applications in signal processing and cryptography