dot-betahatqr: Estimates of Regression Coefficients \boldsymbol{\hat{beta}}...

Description Usage Arguments Value Author(s) References See Also Examples

Description

Estimates coefficients of a linear regression model using QR Decomposition. The data matrix \mathbf{X} is decomposed into

\mathbf{X} = \mathbf{Q} \mathbf{R} .

Estimates are found by solving \boldsymbol{\hat{β}} in

\mathbf{R} \boldsymbol{\hat{β}} = \mathbf{Q}^{T} \mathbf{y}.

Usage

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.betahatqr(X, y)

Arguments

X

n by k numeric matrix. The data matrix \mathbf{X} (also known as design matrix, model matrix or regressor matrix) is an n \times k matrix of n observations of k regressors, which includes a regressor whose value is 1 for each observation on the first column.

y

Numeric vector of length n or n by 1 matrix. The vector \mathbf{y} is an n \times 1 vector of observations on the regressand variable.

Value

Returns \boldsymbol{\hat{β}}, that is, a k \times 1 vector of estimates of k unknown regression coefficients estimated using ordinary least squares.

Author(s)

Ivan Jacob Agaloos Pesigan

References

Wikipedia: Linear regression

Wikipedia: Ordinary least squares

Wikipedia: QR decomposition

Wikipedia: Orthogonal decomposition methods

Wikipedia: Design matrix

See Also

Other beta-hat functions: .betahatnorm(), .betahatsvd(), .intercepthat(), .slopeshatprime(), .slopeshat(), betahat(), intercepthat(), slopeshatprime(), slopeshat()

Examples

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# Simple regression------------------------------------------------
X <- jeksterslabRdatarepo::wages.matrix[["X"]]
X <- X[, c(1, ncol(X))]
y <- jeksterslabRdatarepo::wages.matrix[["y"]]
.betahatqr(X = X, y = y)

# Multiple regression----------------------------------------------
X <- jeksterslabRdatarepo::wages.matrix[["X"]]
# age is removed
X <- X[, -ncol(X)]
.betahatqr(X = X, y = y)

jeksterslabds/jeksterslabRlinreg documentation built on Jan. 7, 2021, 8:30 a.m.