Map the function fn over the elements elems and return the outputs.

`k_map_fn(fn, elems, name = NULL, dtype = NULL)`

Tensor with dtype `dtype`

.

- fn
Function that will be called upon each element in elems

- elems
tensor

- name
A string name for the map node in the graph

- dtype
Output data type.

This function is part of a set of Keras backend functions that enable lower level access to the core operations of the backend tensor engine (e.g. TensorFlow, CNTK, Theano, etc.).

You can see a list of all available backend functions here: https://tensorflow.rstudio.com/reference/keras/index.html#backend.