Notation

  • We will use to represent the number of distinct data points, or observations.

  • Let denote the number of variables that are available for use in making predictions.

  • We will let represent the value of the th variable for the th observation, where , .

  • We let denote a matrix whose th element is .That is,

  • We denote as the th row of . is a vector of length , containing the variable measurements for the th observation. That is,

,+ If we are interested in the columns of , which we will write as . Each is a vector of length , That is,

  • If we use these notations, we can write as

  • The notation denotes the transpose of a matrix or vector. For example, while

  • We use to denote the th observation of the variable on which we wish to predict. Hence, we write the set of all observations in vector form as

  • We always denote a vector of length n in lower case bold e.g.

  • If a vector not of length n will be denoted in lower case normal font, e.g. .

  • Matrix will be denoted using bold capitals, such as .

  • Random variables will be denoted using capital normal font, e.g. , regardless of their dimensions.

  • To indicate that an object is a scalar, we will use the notation . To indicate that it is a vector of length , we will use . We will indicate that an object is a matrix using .

  • Suppose that and . Then the product of and is denoted . That is, . As an example, consider Then

results matching ""

    No results matching ""