Mathematical Notations
Notation | Definition |
|---|---|
 or  | The number of observations in a tabular
dataset. Typically is used, but sometimes
is required to distinguish two datasets, e.g., the
training set and the inference set. |
 or  | The number of features in a tabular dataset. Typically is used, but
sometimes is required to distinguish two datasets. |
 | The dimensionality of a matrix (dataset) has  rows
(observations) and  columns (features). |
 | The vertex set in a graph. |
 | The edge set in a graph. |
 ,  or  | The vertex in a graph. |
 | The edge in a graph. |
 | Depending on the context may be interpreted as follows:
|
 | The  -norm of a vector  , |
 | Sign function for  , |
 | In the description of an algorithm, this typically denotes the
 -th feature vector in the training set. |
 | In the description of an algorithm, this typically denotes the
-th feature vector in the inference set. |
 | In the description of an algorithm, this typically denotes the
-th response in the training set. |
 | In the description of an algorithm, this typically denotes the
-th response that needs to be predicted by the inference
algorithm given the feature vector  from the inference set. |
is a set, this denotes its cardinality, i.e., the number
of elements in the set 
.