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Manipulating an anonymous function

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Will
Will 2014-1-16
评论： per isakson 2014-1-22
I have a handle class myClass which has a property myFunc that is a function handle which I define with an anonymous function, e.g.
myClass.myFunc = @(x) 2*x
Is it possible to use myFunc to redefine itself? I tried
myClass.myFunc = @(x) -myClass.myFunc(x)
but trying to evaluate this led to a max recursion error. My function is defined inside of a class method using a local variable like:
myClass.myFunc = @(x) localVar*x
Otherwise, I would consider using func2str, but that doesn't help because it produces the expression involving localVar which is no longer defined. Right now, I am using
myClass.myOtherFunc = @(x) -myClass.myFunc(x)
but I'd prefer not to have to create a separate property just for this.

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采纳的回答

Walter Roberson
Walter Roberson 2014-1-17
tmp = myClass.myFunc;
myClass.myFunc = @(x) ~tmp(x);
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Walter Roberson
Walter Roberson 2014-1-17
Are you sure you have the (x) after tmp ? Could you show the exact two lines of code that you use?
Will
Will 2014-1-21
Sorry, your solution works for me now. I tried it before and got the error I mentioned, but maybe I had a typo somewhere.

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更多回答（1 个）

per isakson
per isakson 2014-1-17
编辑：per isakson 2014-1-17
I don't understand what you want to achieve, but
>> myc = my_class();
>> x = myc.foo(5);
>> x
x =
-10
where
classdef my_class
properties
foo1
end
methods
function this = my_class( )
this.foo1 = @(x) 2*x;
this.foo1 = @(x) -this.foo1(x);
end
function out = foo( this, val )
out = this.foo1(val);
end
end
end
  2 个评论
Will
Will 2014-1-21
That is basically what I was trying to do. If you change the first line of your class definition from
classdef my_class
to
classdef my_class < handle
you will get a max recursion error when you run myc.foo(5).
per isakson
per isakson 2014-1-22
My mistake. However, this looks like a bug to me. Did you report to tech-support?

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