行空间与列空间 Row and column spaces
有实数元素的m × n 矩阵的行空间是R的由这个矩阵的行矢量生成的子空间。它的维度等于矩阵的秩,最大为min(m,n)。
有实数元素的m × n 矩阵的列空间是R的由这个矩阵的列矢量生成的子空间。它的维度等于矩阵的秩,最大为min(m,n)。
如果把矩阵当作从R到R的线性变换,则矩阵的列空间等于这个线性变换的像。
矩阵A的列矢量是所有A的纵列的线性组合。如果A = [a1, ...., an],则Col A = Span {a1, ...., an}。
行空间的概念推广到了在任何域上的矩阵,特别是复数域C。

![The column vectors of a matrix. The column space of this matrix is the vector space generated by linear combinations of the column vectors.
In linear algebra, the row space of a matrix is the set of all possible linear combinations of its row vectors. Let K be a field (such as real or complex numbers). The row space of an m × n matrix with components from K is a linear subspace of the n-space Kn. The dimension of the row space is called the row rank of the matrix.[1]
A definition for matrices over a ring K (such as integers) is also possible.[2]
vector space generated by linear combinations of the column vectors.](/uploads/202502/08/Matrix_Columns.svg2631.png)