Ok..How to put matrices above matrix when you work with complex equations? I have matrices, such as:    I was able to wrote equation in the LaTeX first two matrices on bottom, but the 1x1 matrix on top seems unreal to write in LaTeX.  Here is my code:  \begin{bmatrix}   (\textbf{u}_{1}\textbf{v}_{1}) &amp; \cdots &amp; (\textbf{u}_{1}\textbf{v}_{n}) \\   \vdots &amp; \ddots &amp; \vdots \\   (\textbf{u}_{n}\textbf{v}_{1}) &amp; \cdots &amp; (\textbf{u}_{n}\textbf{v}_{n}) \end{bmatrix}   Any suggestions regarding that matrix on very top shown in the attached picture?
124035
How can I write a matrix with a header line that is not bracketed? I have used the following code to produce the results below. In addition of being ugly, it is impractical when I need to align the first row, n1, ..., n6 with the matrix columns.  \documentclass{book}  \usepackage{amsmath}    \begin{document}    \[ \ \ \ \ \ \ \ n_1\ \ \ \ \ \ \ \ n_2\ \ \ \ n_3\ \ \ \ \ \ \ \ \ n_4\ \ \ \ n_5\ \ \ \ n_6\]     \[ \begin{bmatrix}         1 &amp; -1 &amp; 0 &amp; 0 &amp; 0 &amp; 1\\         0.960 &amp; -0.977 &amp; 0 &amp; 0 &amp; 0 &amp; 0.983\\         0 &amp; 1 &amp; -1 &amp; -1 &amp; 0 &amp; 0\\         0 &amp; 0.977 &amp; 0 &amp; -0.983 &amp; 0 &amp; 0\\         0 &amp; 0 &amp; 0 &amp; 1 &amp; -1 &amp; -1\\         0 &amp; 0 &amp; 0 &amp; 0 &amp; 0 &amp; 1\\        \end{bmatrix}        \begin{bmatrix}n_1\\n_2\\n_3\\n_4\\n_5\\n_6\end{bmatrix} =        \begin{bmatrix}0 \\ 0 \\ 0 \\ 0 \\ 0 \\ 100\end{bmatrix} \]  \end{document}
2524
I would like to put an underbrace below the matrix like this:  $$\left(\underbrace{ \left[\begin{array}{ccc}     a&amp;b&amp;c\\     d&amp;e&amp;f\\     g&amp;h&amp;i \end{array}\right]}_{A} \left[\begin{array}{c}     x_1\\     x_2\\     x_3 \end{array}\right]\right)$$     But I don't want the outer brackets \left( and \right) to stretch vertically. I want them to remain as if there was no underbrace. How to achieve that behaviour?
69921
I'm currently working on writing something in latex that requires many usages of diagonal matrices of form   $\begin{bmatrix*}     \lambda_1 &amp; 0 &amp; 0\\     0 &amp; \lambda_2 &amp; 0\\     0 &amp; 0 &amp; \lambda_3\\  \end{bmatrix*}$   with a variable number of parameters \lambda.  Previously, I've found a script that helped me create vectors with multiple parameters and therefore save me from rewriting the matrix for them:  \newcommand{\vect}[1]{% \begin{bmatrix} #1\checknextarg} \newcommand{\checknextarg}{\@ifnextchar\bgroup{\gobblenextarg}{ \end{bmatrix}}} \newcommand{\gobblenextarg}[1]{ \\ #1\@ifnextchar\bgroup{\gobblenextarg}{ \end{bmatrix}}}   While this script works for vectors, I can't think of a generalized way to make something similar to this for diagonal matrices. Finding a script like that will save me a ton of time. I've tries using lualatex for this but I'm inexperienced with it and this doesn't help with trying to have a variable amount of parameters and a corresponding amount of 0s. What I hope for is for the example above, I would simply be able to do something like $\diagmat{\lambda_1}{\lambda_2}{\lambda_3}$ for any amount of parameters, similar to what I can do with \vect. While I'm not sure if this is possible, anything that can save me time and space in writing these matrices would be appreciated.
68481
Is it possible to divide a matrix by another? If yes, What will be the result of $\dfrac AB$ if $$         A = \begin{pmatrix}         a &amp; b \\         c &amp; d \\         \end{pmatrix},         B = \begin{pmatrix}         w &amp; x \\         y &amp; z \\         \end{pmatrix}? $$
20990
I'm new to LaTex, and would like to create a table that looks as follows:    How can this be done in LaTex?  Thanks.
5446
How could I go about setting the 'above' and 'below' vspaces around the equation environment?  If the same could be done for the subequations or gather environments, this would be a bonus.
102104
I am writing some proofs using LaTeX, and following the standard procedure in the ConTeXt, I need to write something as follows:    However, I have no idea how to create the "double bracket", like the one includes x := y + z...  Could anyone give me some help on this?
28119
What is the "best LaTeX practices" for writing absolute value symbols?  Are there any packages which provide good methods?  Some options include |x| and \mid x \mid, but I'm not sure which is best...
117586
In Matlab I can create a matrix by typing A = [1 2 3; 4 5 6; 7 8 9], for this the space is a delimiter between the entries of the matrix.  I am wondering if there is a package which makes it possible to input a numerical array in a similar way directly into LaTeX?    For example, I would want to use the syntax:  $\SpaceDelimMat[c]{1 2 3; 4 5 6; 7 8 9}$,   instead of typing &amp; (ampersand) 6 times like this:  $\left[\begin{array}[c]{rrr} 1 &amp; 2 &amp; 3\\ 4 &amp; 5 &amp; 6\\ 7 &amp; 8 &amp; 9\end{array}\right]$;   as to do the latter is very time consuming and makes LaTeX document less readable, especially when presenting a course about Matrices.
65248
I'm getting errors in a matrix equation. When I compile it looks fine, but I'd like to fix them so I don't have to press return for every error at compile time. The code for the equation is:  \begin{equation*}  \begin{bmatrix} U(1,t)  &amp; \cdots &amp; U(n,t) \\  \vdots &amp; \ddots &amp; \vdots \\ O_{n1} &amp; \cdots &amp; O_{nn}  \end{bmatrix} \times \begin{bmatrix} W(1,1)  &amp; \cdots &amp; W(1,n) \\  \vdots &amp; \ddots &amp; \vdots \\  W(n,1) &amp; \cdots &amp; W(n,n)  \end{bmatrix} = \begin{bmatrix}  D(1,t)  &amp; \cdots &amp; D(n,t) \\ \vdots &amp; \ddots &amp; \vdots \\ I_{n1} &amp; \cdots &amp; I_{nn} \end{bmatrix}  \end{equation*}   The errors I'm getting are related to missing $'s inserted.
75261
I'm trying to put equation numbers next to text as if said text was an equation. If I use \text{} in an align* environment, it typesets the text right-aligned and the whole environment centered, but that's not what I want. I would like the text to look like in an itemize or enumerate environment (for example, indented), but still with an equation number behind it. And that equation number should come from the regular equation number "pool".  Ideally, it would look like this:  We have to make sure that:   A is very b,             (1)   A is not c.              (2)   How can I write this in LaTeX?
55179
Following recommendation of  answer I've recently read the series of articles of Wolfire about linear algebra. I'm somewhat familiar with matrices and I came to a conclusion that vector and a matrix multiplication is in fact multiplication of 2x2 and 2x1 matrices:  \begin{equation*} \begin{bmatrix} a &amp; c \\ b &amp; d \end{bmatrix} \qquad \begin{bmatrix} x \\ y \end{bmatrix} \end{equation*}  In  the author reveals that to accomplish translation in addition to rotation we need to add a row and a column to the translation matrix:     If we want to translate by a vector (e,f), we can just tack it onto our change-of-basis matrix like this:   \begin{bmatrix} a &amp; c &amp; e\\ b &amp; d &amp; f\\ 0 &amp; 0 &amp; 1 \end{bmatrix}   And then we add an extra  to the end of each position vector like this:   \begin{bmatrix} x\\ y\\ 1 \end{bmatrix}   P.S. I edited the direction of the vector to make it comply with matrix multiplication conditions.  The 1 at the third row of the vector is totally understandable: to multiply 2x3 matrix we need a 3-row matrix.  What I didn't get here is why we need extra row for translation matrix? I can't see any difference in multiplication (except for the useless 1):  \begin{equation*} \begin{bmatrix} a &amp; c &amp; e\\ b &amp; d &amp; f\\ 0 &amp; 0 &amp; 1 \end{bmatrix} * \begin{bmatrix} x\\ y\\ 1 \end{bmatrix} = \begin{bmatrix} ax + cy + e\\ bx + dy + f\\ 0 + 0 + 1 \end{bmatrix} \end{equation*}  \begin{equation*} \begin{bmatrix} a &amp; c &amp; e\\ b &amp; d &amp; f\\ \end{bmatrix} * \begin{bmatrix} x\\ y\\ 1 \end{bmatrix} = \begin{bmatrix} ax + cy + e\\ bx + dy + f\\ \end{bmatrix} \end{equation*}  So the same question for 3D matrices, just it's easier to convey with a 2D case
62089
I have a problem regarding alignment for my equations.  This dummy program shows the problem:  \documentclass{article} \usepackage{amsmath} \begin{document}  \begin{enumerate}     \item First do this     \begin{align}     c^2 &amp;= a^2 + b^2     \end{align}      \item Then do this      \begin{align}     variable &amp;= c^2     \end{align} \end{enumerate}  \end{document}     I would like the = to be aligned under each other, but still be able to list them inside the enumerate.  Any suggestions?
118513
I have matrices for my syllabus but I don't know where they find their use. I even asked my teacher but she also has no answer. Can anyone please tell me where they are used? And please also give me an example of how they are used?
106174
Some material I'm creating requires output that looks like this:  (note the position of the arrows).    I'm using the following code (with the AMS macros) to generate this, and I'm looking for comments - it works fine, but I'm curious if there's a better/cleaner way to deal with the arrows:  \[   \begin{bmatrix}[rrr|r] 1 &amp; 2 &amp; 0 &amp; -1 \\ 2 &amp; 1 &amp; 1 &amp; 1 \\ -1 &amp; 1 &amp; -1 &amp; -1   \end{bmatrix}   \begin{matrix}[c] ~ \\ \xrightarrow{R_2-2R_1} \\ \xrightarrow{R_3+R_1} \end{matrix}   \begin{bmatrix}[rrr|r] 1 &amp; 2 &amp; 0 &amp; -1 \\ 0 &amp; -3 &amp; 1 &amp; 3 \\ 0 &amp; 3 &amp; -1 &amp; -2 \end{bmatrix}   \begin{matrix}[c] ~ \\ ~ \\ \xrightarrow{R_2+R_3} \end{matrix}   \begin{bmatrix}[rrr|r] 1 &amp; 2 &amp; 0 &amp; -1 \\ 0 &amp; -3 &amp; 1 &amp; 3 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{bmatrix} \]   I'm using only the standard AMS macros, together with a cute addition to the matrix macros that I found on the Web that allows column specifications within the AMS matrices:  \makeatletter \renewcommand*\env@matrix[1][*\c@MaxMatrixCols c]{%   \hskip -\arraycolsep   \let\@ifnextchar\new@ifnextchar   \array{#1}} \makeatother
23791
How do we add a matrix to a LaTeX document?
18877
I have to write something under the symbol \bullet in Latex. Is it possible? I'm using the class beamer. Here it is an example of a frame:  \begin{frame} \begin{itemize} \item&lt;1-&gt; Products Market\mbox{}\\ \footnotesize{where $p_{i,t}=u_{i,t}$, with $u_{i,t}\sim u[0,2]$} \vspace{0.5cm} \item&lt;2-&gt; Credit Market \mbox{} \vspace{0.2cm} \\ \footnotesize{where \hspace{0.1cm} $\bullet_{bank} \xrightarrow{loan} \bullet$} \vspace{0.5cm} \item&lt;3-&gt; Interbank Market\mbox{} \vspace{0.08cm} \\ \footnotesize{where \hspace{0.1cm} $\bullet \xrightarrow{loan} \bullet$} \end{itemize} \end{frame}   In particular I want to write "bank" under the bullet, while now it is only in subscript.  Thanks