Olympic puzzle number one

Daniel has provided this nice puzzler:

clear = @()disp('Have fun undoing this (:');

Let's solve this challenge and restore the original clear command in as many ways as you find.

[John Petersen]

Would somebody please answer this so I can use clear again? aaaah... Thanks Mike!!

[Daniel Shub]

Credit should really be given to Loren.

[Jan]

Yes, extra credits for Loren. Extra point for Daniel for the link to Loren's blog!

Answer 1

[Sean de Wolski]

system('matlab &');quit

[Jan]

The rebirth method! +1 from Heidelberg!

On stage deeper: WinPower('rebootmatlab', 'which clear -all') I've always known that this tool will be useful for anything sometimes.

Answer 2

[Mike Hosea]

1. builtin('clear','clear')
2. You can delete the variable from the workspace window (highlight and press delete or right click and delete).

I look forward to reading some more creative ways.

[Jan]

First! Thanks for taking the builtin out of the race. The workspace browser is an almost external tool to operate in the workspace. +1

[Daniel Shub]

I wonder if the workspace window method method can be accessed by a java method from the commandline.

Answer 3

[Sean de Wolski]

clear = rand(1000,500,700);
pack

[Daniel Shub]

I like this solution.

[Jan]

Relief by much beef. The weight-lifting method.

Answer 4

[Daniel Shub]

Missing from the obvious solutions are:

clear = str2func('clear'); clear();

and

feval('clear');

[Sean de Wolski]

Nice! I would've thought the str2func solution would have recursively called itself.

[Jan]

Re-identification using str2func is fine. I'm surprised that feval does not fail. Most of all: The first approach contains "clear" three times. This is the winner in synchronized swimming.

[Mike Hosea]

If you wanted to leave the rest of the workspace undisturbed it would have been four mentions of "clear":

clear = str2func('clear'); clear('clear');

Answer 5

[Daniel Shub]

Somewhat surprisingly the CLEARVARS function is not a solution and gives an unhelpful error message. I think the failure probably qualifies as a bug.

[Sean de Wolski]

clearvars is just a fancy wrapper for evalin with clear.

edit clearvars

[Jan]

Disqualified. Who cares, the most important thing is not to win but to take part!

[Daniel Shub]

@Sean, my point was that it could be a slightly fancy wrapper that could catch this error