Page 84 - Excel for Scientists and Engineers: Numerical Methods
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CHAPTER 3 MATRICES 61
Do not type the braces; if you do, the result will not be recognized by Excel
as a formula.
Figure 3-2. Result matrix {A + 3).
(folder 'Chapter 03 (Matrices) Examples, workbook 'Matrix Math', sheet 'Sheet 1')
Subtraction of a constant, multiplication or division by a constant, or addition
of two matrices is performed in the same way by using standard Excel algebraic
operators.
Scalar Multiplication. Scalar multiplication can be either multiplication of
the elements of a matrix by a constant, e.g., a formula such as {=3*A}, or
multiplication of corresponding elements of two matrices, e.g., {=A*B}. The
result of the latter formula is shown in Figure 3-3.
Figure 3-3. Result matrix {A x B} .
(folder 'Chapter 03 (Matrices) Examples, workbook 'Matrix Math', sheet 'Sheet 1 ')
Matrix multiplication can be accomplished easily by the use of Excel's
worksheet function MMULT(mafrix7, mafrix2). For the matrices A and B
defined above, entering the formula =MMULT(A,B) yields the result shown in
Figure 3-4 while the formula =MMULT(B,A) yields the result shown in Figure
3-5.
Figure 3-4. Result matrix A.B.
(folder 'Chapter 03 (Matrices) Examples, workbook 'Matrix Math', sheet 'Sheet 1 ')
