\documentclass[10pt]{article} %\usepackage{amsbsy} % for \boldsymbol and \pmb %\usepackage{graphicx} % To include pdf files! \usepackage{amsmath} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage[colorlinks=true, pdfstartview=FitV, linkcolor=blue, citecolor=blue, urlcolor=blue]{hyperref} % For links \oddsidemargin=0in % Good for US Letter paper \evensidemargin=0in \textwidth=6.3in \topmargin=-0.5in \headheight=0.1in \headsep=0.1in \textheight=9.4in \pagestyle{empty} % No page numbers \begin{document} \enlargethispage*{1000 pt} \begin{center} {\Large \textbf{STA 302 Formulas}}\\ % Version 1 \vspace{1 mm} \end{center} % Spectral decomposition, linear independence. % MGFs % Random vectors % Linear model % Distribution facts, incl x2 addup? % Test stats and CIs \noindent \renewcommand{\arraystretch}{2.0} \begin{tabular}{lll} \multicolumn{3}{l}{Columns of $\mathbf{A}$ \emph{linearly dependent} means there is a vector $\mathbf{v} \neq \mathbf{0}$ with $\mathbf{Av} = \mathbf{0}$.} \\ \multicolumn{3}{l}{Columns of $\mathbf{A}$ \emph{linearly independent} means that $\mathbf{Av} = \mathbf{0}$ implies $\mathbf{v} = \mathbf{0}$.} \\ $\boldsymbol{\Sigma} = \mathbf{CD} \mathbf{C}^\prime$ & ~~~~~ & $\boldsymbol{\Sigma}^{-1} = \mathbf{C} \mathbf{D}^{-1} \mathbf{C}^\prime$ \\ $\boldsymbol{\Sigma}^{1/2} = \mathbf{CD}^{1/2} \mathbf{C}^\prime$ & ~~~~~ & $\boldsymbol{\Sigma}^{-1/2} = \mathbf{CD}^{-1/2} \mathbf{C}^\prime$ \\ $M_Y(t) = E(e^{Yt})$ & ~~~~~ & $M_{aY}(t) = M_Y(at)$ \\ $M_{Y+a}(t) = e^{at}M_Y(t)$ & ~~~~~ & $M_{\sum_{i=1}^n Y_i}(t) = \prod_{i=1}^n M_{Y_i}(t)$ \\ $Y \sim N(\mu,\sigma^2)$ means $M_Y(t) = e^{\mu t + \frac{1}{2}\sigma^2t^2}$ & ~~~~~ & $Y \sim \chi^2(\nu)$ means $M_Y(t) = (1-2t)^{-\nu/2}$ \\ \multicolumn{3}{l}{If $W=W_1+W_2$ with $W_1$ and $W_2$ independent, $W\sim\chi^2(\nu_1+\nu_2)$, $W_2\sim\chi^2(\nu_2)$ then $W_1\sim\chi^2(\nu_1)$} \\ $cov(\mathbf{Y}) = E\left\{(\mathbf{Y}-\boldsymbol{\mu}_y)(\mathbf{Y}-\boldsymbol{\mu}_y)^\prime\right\}$ & ~~~~~ & $C(\mathbf{Y,T}) = E\left\{ (\mathbf{Y}-\boldsymbol{\mu}_y) (\mathbf{T}-\boldsymbol{\mu}_t)^\prime\right\}$ \\ $cov(\mathbf{Y}) = E\{\mathbf{YY}^\prime\} - \boldsymbol{\mu}_y\boldsymbol{\mu}_y^\prime$ & ~~~~~ & $cov(\mathbf{AY}) = \mathbf{A}cov(\mathbf{Y}) \mathbf{A}^\prime$ \\ $M_{\mathbf{Y}}(\mathbf{t}) = E(e^{\mathbf{t}^\prime\mathbf{Y}})$ & ~~~~~ & $M_{\mathbf{AY}}(\mathbf{t}) = M_{\mathbf{Y}}(\mathbf{A}^\prime\mathbf{t})$ \\ $M_{\mathbf{Y}+\mathbf{c}}(\mathbf{t}) = e^{\mathbf{t}^\prime\mathbf{c}} M_{\mathbf{Y}}(\mathbf{t})$ & ~~~~~ & $\mathbf{Y} \sim N_p(\boldsymbol{\mu}, \boldsymbol{\Sigma})$ means $M_{\mathbf{Y}}(\mathbf{t}) = e^{\mathbf{t}^\prime\boldsymbol{\mu} + \frac{1}{2} \mathbf{t}^\prime \boldsymbol{\Sigma} \mathbf{t}}$ \\ \multicolumn{3}{l}{$\mathbf{Y}_1$ and $\mathbf{Y}_2$ are independent if and only if $M_{(\mathbf{Y}_1,\mathbf{Y}_2)^\prime}\left((\mathbf{t}_1,\mathbf{t}_2)^\prime\right) = M_{\mathbf{Y}_1}(\mathbf{t}_1) M_{\mathbf{Y}_2}(\mathbf{t}_2)$} \\ If $\mathbf{Y} \sim N_p(\boldsymbol{\mu}, \boldsymbol{\Sigma})$, then $\mathbf{AY} \sim N_q(\mathbf{A}\boldsymbol{\mu}, \mathbf{A}\boldsymbol{\Sigma}\mathbf{A}^\prime)$, & ~~~~~ & and $W = (\mathbf{Y}-\boldsymbol{\mu})^\prime \boldsymbol{\Sigma}^{-1}(\mathbf{Y}-\boldsymbol{\mu}) \sim \chi^2(p)$ \\ $r_{xy} = \frac{\sum_{i=1}^n (X_i-\overline{X})(Y_i-\overline{Y})} {\sqrt{\sum_{i=1}^n (X_i-\overline{X})^2} \sqrt{\sum_{i=1}^n (Y_i-\overline{Y})^2}}$ & ~~~~~ & \\ $Y_i = \beta_0 + \beta_1 x_{i1} + \cdots + \beta_k x_{ik} + \epsilon_i$ & ~~~~~ & $\epsilon_1, \ldots, \epsilon_n$ independent $N(0,\sigma^2)$ \\ $\mathbf{Y} = \mathbf{X} \boldsymbol{\beta} + \boldsymbol{\epsilon}$ & ~~~~~ & $\boldsymbol{\epsilon} \sim N_n(\mathbf{0},\sigma^2\mathbf{I}_n)$ \\ $\widehat{\boldsymbol{\beta}} = (\mathbf{X}^\prime \mathbf{X})^{-1} \mathbf{X}^\prime \mathbf{Y} $ & ~~~~~ & $\widehat{\mathbf{Y}} = \mathbf{X}\widehat{\boldsymbol{\beta}} = \mathbf{HY}$, where $\mathbf{H} = \mathbf{X}(\mathbf{X}^\prime \mathbf{X})^{-1} \mathbf{X}^\prime $ \\ $\sum_{i=1}^n(Y_i-\overline{Y})^2 = \sum_{i=1}^n(Y_i-\widehat{Y}_i)^2 + \sum_{i=1}^n(\widehat{Y}_i-\overline{Y})^2$ & ~~~~~ & $SST=SSE+SSR$ and $R^2 = \frac{SSR}{SST}$ \\ $\widehat{\boldsymbol{\epsilon}} = \mathbf{Y} - \widehat{\mathbf{Y}}$ & ~~~~~ & $\widehat{\boldsymbol{\beta}} \sim N_{k+1}\left(\boldsymbol{\beta}, \sigma^2 (\mathbf{X}^\prime \mathbf{X})^{-1}\right)$ \\ $\widehat{\boldsymbol{\beta}}$ and $\widehat{\boldsymbol{\epsilon}}$ are independent under normality. & ~~~~~ & $SSE/\sigma^2 = \hat{\boldsymbol{\epsilon}}^\prime \hat{\boldsymbol{\epsilon}}/\sigma^2 \sim \chi^2(n-k-1)$ \\ $T = \frac{Z}{\sqrt{W/\nu}} \sim t(\nu)$ & ~~~~~ & $F = \frac{W_1/\nu_1}{W_2/\nu_2} \sim F(\nu_1,\nu_2)$ \\ $T = \frac{\mathbf{a}^\prime \widehat{\boldsymbol{\beta}}-\mathbf{a}^\prime \boldsymbol{\beta}} {s \, \sqrt{\mathbf{a}^\prime (\mathbf{X}^\prime \mathbf{X})^{-1}\mathbf{a}}} \sim t(n-k-1)$ & ~~~~~ & $T = \frac{Y_0-\mathbf{x}_0^\prime \widehat{\boldsymbol{\beta}}} {s \, \sqrt{(1+\mathbf{x}_0^\prime (\mathbf{X}^\prime \mathbf{X})^{-1}\mathbf{x}_0)}} \sim t(n-k-1)$ \\ \multicolumn{3}{l}{$F = \frac{(\mathbf{C}\widehat{\boldsymbol{\beta}}-\mathbf{t})^\prime (\mathbf{C}(\mathbf{X}^\prime \mathbf{X})^{-1}\mathbf{C}^\prime)^{-1} (\mathbf{C}\widehat{\boldsymbol{\beta}}-\mathbf{t})} {q \, s^2} = \frac{SSR-SSR(reduced)}{q \, s^2} \sim F(q,n-k-1)$, where $s^2 = MSE = \frac{SSE}{n-k-1}$} \\ \end{tabular} \renewcommand{\arraystretch}{1.0} %\vspace{10mm} \noindent \begin{center}\begin{tabular}{l} \hspace{6.5in} \\ \hline \end{tabular}\end{center} This formula sheet was prepared by \href{http://www.utstat.toronto.edu/~brunner}{Jerry Brunner}, Department of Statistics, University of Toronto. It is licensed under a \href{http://creativecommons.org/licenses/by-sa/3.0/deed.en_US} {Creative Commons Attribution - ShareAlike 3.0 Unported License}. Use any part of it as you like and share the result freely. The \LaTeX~source code is available from the course website: \href{http://www.utstat.toronto.edu/~brunner/oldclass/302f13} {\texttt{http://www.utstat.toronto.edu/$^\sim$brunner/oldclass/302f13}} \end{document} \noindent ~~If $\mathbf{Y} \sim N_p(\boldsymbol{\mu},\boldsymbol{\Sigma} )$, then $\mathbf{AY} \sim N_r(\mathbf{A}\boldsymbol{\mu}, \mathbf{A}\boldsymbol{\Sigma}\mathbf{A}^\prime )$. \vspace{3mm} \noindent ~~If $E(\mathbf{Y})=\boldsymbol{\mu}$, then $V(\mathbf{Y})$ is defined by $V(\mathbf{Y}) = E\left\{(\mathbf{Y}-\boldsymbol{\mu})(\mathbf{Y}-\boldsymbol{\mu})^\prime\right\}$. \vspace{3mm} \multicolumn{3}{l}{If $X \sim N(\mu,\sigma^2)$, then $\frac{X^2}{\sigma^2} \sim \chi^2(1,\lambda)$, with $\lambda = \frac{\mu^2}{\sigma^2}$} \\ $\phi = \frac{(\mathbf{L}\boldsymbol{\beta}-\mathbf{h})^\prime (\mathbf{L}(\mathbf{X}^\prime \mathbf{X})^{-1}\mathbf{L}^\prime)^{-1} (\mathbf{L}\boldsymbol{\beta}-\mathbf{h})} {\sigma^2}$ & ~~~~~ & \\ $f(y|\theta,\phi) = \exp\left\{ \frac{y\theta-b(\theta)}{\phi} + c(y,\phi)\right\}$ & ~~~~~ & $\theta = g(\mu) = \eta = \mathbf{x}^\prime\boldsymbol{\beta}$ \\