In mathematics a single-entry matrix is a matrix where a single element is one and the rest of the elements are zero, e.g., J 23 = . {\displaystyle \mathbf {J} ^{23}=\left.} It is a specific type of a sparse matrix.
在数学中，单元素矩阵是一个矩阵，其中只有一个元素为一，其余元素为零，例如： J 23 =  . {\displaystyle \mathbf {J} ^{23}=\left.} 它是稀疏矩阵的特定类型。