I hope this question is the most suitable in this site...
In Python, usually the class name is defined using the capital letter as its first character, for example
class Vehicle: ...
However, in machine learning field, often times train and test data are defined as
Y - not
y. For example, I'm now reading this tutorial on Keras, but it uses the
Y as its variables:
from sklearn import datasets mnist = datasets.load_digits() X = mnist.data Y = mnist.target
Why are these defined as capital letters? Is there any convention (at least in Python) among machine learning field that it is better to use the capital letter to define these variables?
Or maybe do people distinguish the upper vs lower case variables in machine learning?
In fact the same tutorial later distinguish these variables like the following:
from sklearn.cross_validation import train_test_split train_X, test_X, train_y, test_y = train_test_split(X, Y, train_size=0.7, random_state=0)