Question 1. How to input multiple variables (features) x1, x2, x3...x10 which are in categorical in nature to neural network. Basically I want to know how will I prepare my input layer to neural network. Below is the sample example of my data set.
x1, x2, x10 Y
A, Red A10 1
B, Blue A20 2
C, Green A30 3
I have googled on this, some say use one-hot encoding. But I am not sure how will I apply one hot encoding technique to all the feature I have and how the input matrix structure will be.
If I have only one feature say x1. I understand I can apply one-hot encoding.
A: 1 0 0
B: 0 1 0
C: 0 0 1
And this 3x3 matrix can be used as input layer to Neural network.
[3x3] -> [Neural Network] -> [out]
But I have multiple feature here x1, x2 ... x10. How will I frame my input layer, what will the input layer structure. Please advise.
Question 2
Also, variable x2, x10 might get new categorical value which is not seen in training set (for eg. X10 = Z99 ) how to handle this problem.