Our data which we want to apply a machine learning method on, consist of a set of inputs \( \boldsymbol{x}^T=[x_0,x_1,x_2,\dots,x_{n-1}] \) and the outputs we want to model \( \boldsymbol{y}^T=[y_0,y_1,y_2,\dots,y_{n-1}] \). We assume that the output data can be represented (for a regression case) by a continuous function \( f \) through
$$ \boldsymbol{y}=f(\boldsymbol{x})+\boldsymbol{\epsilon}. $$