I've noticed that in a python code you can do something like:
a=0
b=1
a,b=b,a
print(a,b)
which outputs (a=1,b=0) (i.e. each variable is assigned independently of the last assignment). Is there a way to do something similar in MATLAB?
Sorry if this is a really simple question, but I've been trying to find a clean answer to this for a bit of time now and haven't found anything.
There is no need for an additional temporary variable here. If you want multiple assignments in a single statement, you can use deal:
[a, b] = deal(b, a)
I believe this is what you're looking for.
deal vs. just creating a temporary variable? The JIT can easily optimize away a temporary variable. Even though deal is not particularly complicated internally, I wonder if it's a good idea to use it when performance matters?
deal was 12 times slower than using a temporary variable. This was constant across a wide range range of variable sizes. Convenience often has a cost.It's always possible to do that with a temporary variable in any language. The unpacking method of Python is just a little syntax sugar to simplify the developer life :)
a = 0
b = 1
tmp = a
a = b
b = tmp
print(a,b)
Anyway, it's not magical, the Python byte code might implement the permutation with a temporary variable. (There's techniques to do this without temp variable, but well... for the sake of clarity use one :p)