MATLAB Programming

3 Basic Program Components
The dynamic expression reverses the order of the letters that make up the
string, and then attempts to match as much of the reversed-order string as
possible. This requires a dynamic expression because the value for $1 relies
on the value of the token (.{3,}):
% Put the string in lowercase.
str = lower(...
'Find the palindrome Never Odd or Even in this string');
% Remove all nonword characters.
str = regexprep(str, '\W*', '')
str =
findthepalindromeneveroddoreveninthisstring
% Now locate the palindrome within the string.
palstr = regexp(str, '(.{3,}).?(??@fliplr($1))', 'match')
str =
'neveroddoreven'
Dynamic expressions in MATLAB have access to the currently active
workspace. This means that you can change any of the functions or variables
used in a dynamic expression just by changing variables in the workspace.
Repeat the last command of the example above, but this time define the
function to be called within the expression using a function handle stored in
the base workspace:
fun = @fliplr;
palstr = regexp(str, '(.{3,}).?(??@fun($1))', 'match')
palstr =
'neveroddoreven'
Dynamic Commands that Serve a Functional Purpose — (?@cmd). The
(?@cmd) operator specifies a MATLAB command that regexp or regexprep
is to run while parsing the overall match expression. Unlike the other
dynamic expressions in MATLAB, this operator does not alter the contents
of the expression it is used in. Instead, you can use this functionality to get
MATLABtoreportjustwhatstepsit’stakingasitparsesthecontentsofone
of your regular expressions.
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