What does 'no_inplace' mean in theano?

Question

Here is the code:

>>> a = T.dscalar("a")
>>> b = a+2
>>> b

and the output is

Elemwise{add,no_inplace}.0

add shows that the apply node has the add as the operation.

But what does no_inplace mean? and why we have a ".0" at the end of the output?

Answer 1

Inplace computations are computations that destroy their inputs as a side-effect. For example, if you iterate over a matrix and double every element, this is an inplace operation because when you are done, the original input has been overwritten. Ops representing inplace computations are destructive, and by default these can only be inserted by optimizations, not user code.

So no_inplace is just the opposite.

From http://deeplearning.net/software/theano/glossary.html#glossary