MATLAB APPLICATION DEPLOYMENT - WEB EXAMPLE GUIDE Guide de l'utilisateur télécharger pdf (Page 74)

3 Working with MEX-Files

3-10

Converting Script M-Files to Function M-Files

MATLAB provides two ways to package sequences of MATLAB commands:

• Function M-files

• Script M-files

These two categories of M-files differ in two important respects:

• You can pass arguments to function M-files but not to script M-files.

• Variables used inside function M-files are local to that function; you cannot

access these variables from the MATLAB interpreter’s workspace unless

they are passed back by the function. By contrast, variables used inside

script M-files are shared with the caller’s workspace; you can access these

variables from the MATLAB interpreter command line.

The MATLAB Compiler cannot compile script M-files nor can it compile a

function M-file that calls a script.

Converting a script into a function is usually fairly simple. To convert a script

to a function, simply add a

function line at the top of the M-file.

For example, consider the script M-file

houdini.m:

m = magic(4); % Assign 4x4 matrix to m.

t = m .^ 3; % Cube each element of m.

disp(t); % Display the value of t.

Running this script M-file from a MATLAB session creates variables m and t in

your MATLAB workspace.

The MATLAB Compiler cannot compile

houdini.m because houdini.m is a

script. Convert this script M-file into a function M-file by simply adding a

function header line:

function [m,t] = houdini(sz)

m = magic(sz); % Assign matrix to m.

t = m .^ 3; % Cube each element of m.

disp(t) % Display the value of t.

The MATLAB Compiler can now compile houdini.m. However, because this

makes

houdini a function, running houdini.mex no longer creates variable m

1 2 ... 69 70 71 72 73 74 75 76 77 78 79 ... 273 274

Pas de commentaire

MATLAB APPLICATION DEPLOYMENT - WEB EXAMPLE GUIDE Guide de l'utilisateur Page 74