transforming an m-file to an anonymous or inline function

Hi, I have the following function

function out=myfun(x,y,z)
aa=h1(x,y,z);
dd=h2(x,y,z);
out=[x(1)+y(2)
x(3)+z(2)
x(1)+aa
x(3)+dd*y(1)];

Is there any way I can write this function either as inline or anonymous? that is without writing an m-file?

Thanks, J.

Answer 1

[Daniel Shub]

You need to get rid of the temp variables aa and dd:

aa = @(x,y,z)(h1(x,y,z));
dd = @(x,y,z)(h1(x,y,z));
fcn = @(x,y,z)([x(1)+y(2); x(3)+z(2); x(1)+aa(x,y,z); x(3)+dd(x,y,z)*y(1)]);

[Junior]

The very reason I am post the question is because I don't want to insert for aa and dd, which are themselves very complicated expressions. For simplicity, I just defined them as h1(x,y,z) and h2(x,y,z). Thanks, J.

[Daniel Shub]

See my edit. You can keep splitting up h1 and h2 into functions that are whatever size you want. The key is you cannot have any temp variables.

Answer 2

[Fangjun Jiang]

It is not recommended to use anonymous function due to the fact that the function has so many characters. If you wan to make it in line, just remove the first line 'function out=myfun(x,y,z)' and copy the rest of the code into your other M-script or M-function.

[Junior]

Is there any restrictions on the number of characters for an inline function? And about your suggestion of just removing the first line, what to do about the definitions of "aa" and "dd"?

thanks for answering,

J.

[Fangjun Jiang]

What do you mean inline function? You either insert your code above wihtout the function line in-line with your main function (or main script), or you create a function for it.

Anonymous function is no different than ordinary function. If the function is short, you can use anonymous function so you don't have to give it a name and you don't need to create a separate file.

If your main program is also a function, you can make the code above a sun-function in your main function .m file. You don't need to create a separate .m file for it. For example, open importdata.m file, at the top, it is the importdata() function itself. At the bottom, there are many functions that are only available for use by the importdata() function.

[Fangjun Jiang]

Should be subfunctions in my previous comments. Search subfunctions in document for details.

[Daniel Shub]

If your m-file is a script and you want to use a function that requires a function handle (e.g., fminsearch) then you need a second m-file with your function or an anonymous function.