How to Decide no. of units of a layer

Course Q&A Machine Learning Specialization Advanced Learning Algorithms
1

my question is how to decide the no. of units to be used in a layer of classification neural network?
As i have seen that for digit recognition classification problem, there was 25 units in layer-1, 15 units in layer-2 and 10 units in layer-3. But how can we decide no. of units, layers needed for any other problem?

2

Hello @PREM_KISHORE,

Unfortunately there is no formula to predict how to configure the NN for every problem. We usually get to a better (NOT the best) NN by trials and errors and through this process we keep evaluating our current choice of NN architecture with a cv set. Since you are posting this question in the course 2 week 2 category, I would suggest you to also go over the videos in week 3 when the time comes, and get some tastes of how we evaluate the goodness of a model candidate in terms of overfitting and underfitting.

Raymond