# Deep Learning

Deep learning is one of the application of
Neural Network
.
Difference bettween deep learning and old neural network is the number intermediate layers between Y and X.

##
Idea to Build Deep Learning

Deep learning includes the many intermediate layers.

There was the problem to calculate many intermediate layers.
But deep learning solved the problem by pre-learning.

At
Principal component regression analysis,
principal component analysis
is used before
multi-regression analysis
.
And there are approaches that we use SOM
or
cluster analysis
before
decision tree.
These methods are used to make clear the conclusion of the analysis and to strengthen the week-point of
multi-regression analysis
and
decision tree.

The idea of pre-learning in deep learning is similar to these approaches.

##
Free Software

Many package are developed in python.
And H2O, TensorFlow, Keras, MXNet, RSNNS and rnn are also used in R.
.

NEXT Auto Encoder