What does the "no_inplace" mean in theanano?

Question

Here is the code:

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

and the way out is

 Elemwise{add,no_inplace}.0 

Add shows that the node application has an addition as an operation.

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

Answer 1

Inplace calculations are calculations that destroy their inputs as a side effect. For example, if you iterate over a matrix and duplicate each element, this is an inplace operation because when you are done, the original input has been overwritten. Operations representing inplace calculations are disruptive, and by default they 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