MATLAB program instructions

The function in Example 4.4 can be used to autoscale a data matrix. The function determines the size of the argument, its mean vector, and its standard deviation vector. On the last fine, a MATLAB programming trick is used to extend the mean vector and standard deviation vector into matrices having the same number of rows as the original argument prior to subtraction and division. The expression ones < r, i) creates an r x 1 column vector of ones. When used as an index in the statement mn (ones(r,1), ), it instructs MATLAB to replicate the mean vector r times to give a matrix having the dimensions r x c. 

The graphs are designed to be simple but instructive. They do not make use of the richness of the Matlab graphics routines. We did not include any graphical user-interfaces (GUIs) in order to avoid difficulties with different versions of Matlab. Matlab versions starting from 5.3 should be compatible with all programs in this book. 

To summarize the steps, step 1 defined the problem you wished to solve, step 2 checked your programming, and step 3 instructed MATLAB to solve the problem. It is tempting to skip the second step - checking your programming - but remember If the programming is wrong, you will solve the wrong problem. 

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