Page 33 - Computational Colour Science Using MATLAB

20 A SHORT INTRODUCTION TO MATLAB

ans =
0.5000 0.5000
0.5000 -0.5000

and the inverse of M is computed and displayed in the Command Window. At
any time it is possible to type the command whos and this displays a list of the
current variables and their dimensions; thus

>>whos
Name Size Bytes Class
M 2 2 32 double array
ans 2 2 32 double array
p 2 1 16 double array
Grand total is 10 elements using 80 bytes

Note that since we did not assign the output of the inv command to any variable
it was automatically assigned to the variable ans.
We can now compute the solution to Equation (2.2) easily by typing

>>a = inv(M)*p
a=
4.5000
1.5000

which gives, of course, the same result as that achieved by the substitution
method that was briefly described in Chapter 2.
In the following sections the basic properties of MATLAB are briefly
introduced and some of its useful functions are described.

3.1 Matrix operations

Matrices may be added, subtracted and multiplied using the conventional
symbols +, and . Matrices may also be easily augmented thus

>>M = [1 1; 1 -1];
>>M = [M; M]
M=
1 1
1 -1
1 1
1 -1