Appendix B: Introduction to Matrix Algebra

Note that there are j rows and k columns. Also note that the elements are double subscripted, with the row number first, and the column number second. When reading the text, and doing your assignments, you should always keep the dimensionality of matrices in mind. The dimensionality of the matrix is also called the order of a matrix. In general terms, the A above is of order (j, k). Let us look at a couple of examples: