A generalization of Hadamard matrices.
A weighing matrix of order n {\displaystyle n} with weight w {\displaystyle w} is an n × n {\displaystyle n\times n} { 0 , ± 1 } {\displaystyle \{0,\pm 1\}} -matrix such that W W T = w I {\displaystyle WW^{T}=wI} .
