General matrices

Question

I want to use LaTeX to add matrix that looks like this:

-----L_1-----

-----L_2-----

. . . . . . .

----L_n-----

and matrices where I want to show how a general cell in the matrix looks like (for example writing a matrix and then marking that 3 belongs to the i'th row and j'th column) , like here :

enter image description here

(I am not looking to a way to add the vertical lines ,but I want to have a matrix filled with dots, except at the i,j place and there write $2^{i+j}$ [ I want a matrix that each cell has the value of 2^{row number +column number})

Welcome to TeX.SX! I'm pretty sure there's already something like this on the site. — egreg, Feb 18 '15 at 22:54
Thanks :) I am pretty new here , and I didn't know how to explain what I need ... can you help me find this? — UserB95, Feb 18 '15 at 22:55
Perhaps http://tex.stackexchange.com/questions/57411/long-dashes-for-denoting-omitted-columns-of-a-matrix is what you want for the first problem — egreg, Feb 18 '15 at 23:00
And http://tex.stackexchange.com/questions/196258/draw-a-vertical-line-over-the-entries-of-a-column-in-an-array for the second problem. — egreg, Feb 18 '15 at 23:02
@egreg for the first question : can I add dots( I want to say that the matrix has n rows) For the second question : It is not exactly what I meant , I wanted to have a matrix , filled with dots, except at the i,j place and there write $2^{i+j}$ [ I want a matrix that each cell has the value of 2^{row number +column number} — UserB95, Feb 18 '15 at 23:15
There's \hdotsfor in the amsmath package. I'll add to my answer for the first problem. — egreg, Feb 18 '15 at 23:17

score 1 · Answer 1 · edited Apr 13 '17 at 12:35

For the first problem, look at Long dashes for denoting omitted columns of a matrix

For the second problem, the result will not be pretty:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\[
\begin{pmatrix}
\makebox[9em]{\dotfill} \\
\makebox[9em]{\dotfill} \\
\makebox[9em]{\dotfill\ $2^{i+j}$ \dotfill} \\
\makebox[9em]{\dotfill} \\
\makebox[9em]{\dotfill} \\
\end{pmatrix}
\]

\end{document}

I'd very much prefer a simpler description:

The matrix $A=(a_{ij})$ where $a_{ij}=2^{i+j}$, for $1\le i,j\le n$

General matrices

1 Answers1