# Hadamard matrix

> real square matrix whose all columns (rows) are mutually orthogonal and which only 1 or −1 as entries

**Wikidata**: [Q1422682](https://www.wikidata.org/wiki/Q1422682)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Hadamard_matrix)  
**Source**: https://4ort.xyz/entity/hadamard-matrix


## References

1. Freebase Data Dumps. 2013
2. Quora
3. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)