Math & Science ⇒ Matrix cell space and arrows as markers

[salehin]

When I use those arrows along with their marker to denote i'm unable to produce a nice looking matrix [arrow in correct spaces and each cell of equal size]. I've added a complied pdf file as well. Thanks for reading.

Regards,

Ash

Code: Select all

\documentclass[a4paper,12pt, final]{article}
\usepackage{amsmath}
\usepackage[margin=2.54cm,top=2.54cm]{geometry}
\usepackage{hyperref}
\usepackage{amsmath}
\usepackage{amssymb}


\begin{document}

\begin{align*}
& \quad \text{ }\underset{\downarrow }{1}\quad \underset{\downarrow }{k}%
\qquad \underset{\downarrow }{x}\ \underset{\downarrow }{i} \\
H=& \left[
\begin{array}{cccc}
1 & 0 & 0 & 0 \\
0 & 1 & 0 & 0 \\
0 & 0 & 1 & 0 \\
0 & 0 & 0 & 1 \\
1 & 0 & 0 & 0 \\
0 & \left( 1-\rho \right)  & 0 & 1 \\
0 & 0 & \rho  & 0%
\end{array}
\right]
\begin{array}{c}
\leftarrow 1 \\
\leftarrow k \\
\leftarrow x \\
\leftarrow i \\
\leftarrow 1 \\
\leftarrow k^{\prime } \\
\leftarrow x^{\prime }%
\end{array}
\end{align*}

\end{document}

[gmedina]

Hi,

some adjustments can improve your matrix:

Code: Select all

\documentclass[a4paper,12pt, final]{article}
\usepackage{amsmath}
\usepackage[margin=2.54cm,top=2.54cm]{geometry}
\usepackage{hyperref}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{array}

\begin{document}

\[
\begin{array}{c}
  \hspace*{-3pt}%
  \begin{array}{cccc}
    \hphantom{0} & \hphantom{\left( 1-\rho \right)} & \hphantom{0} & \hphantom{0}\\[-15pt]
    1 & k & x & i\\
    \downarrow & \downarrow & \downarrow & \downarrow
  \end{array} \\
  H= \left[%
  \begin{array}{cccc}
    1 & 0 & 0 & 0 \\
    0 & 1 & 0 & 0 \\
    0 & 0 & 1 & 0 \\
    0 & 0 & 0 & 1 \\
    1 & 0 & 0 & 0 \\
    0 & \left( 1-\rho \right)  & 0 & 1 \\
    0 & 0 & \rho  & 0%
  \end{array}
  \right]
  \begin{array}{@{\leftarrow\, }c}
    1 \\
    k \\
    x \\
    i \\
    1 \\
    k^{\prime } \\
    x^{\prime }%
  \end{array}
\end{array}
\]

\end{document}

The bigdelim package could be useful too.

[salehin]

Thanks gmedina.

If possible, can you please advise how to make column width of equal size [, cf. the 3rd and 4th column in this case].

Regards,

Ash

ps: just noticed about the package you've mentioned! I'll have a look at it.

[gmedina]

Hi Ash,

Thanks gmedina.

If possible, can you please advise how to make column width of equal size [, cf. the 3rd and 4th column in this case]...

You are welcome! The first, third and fourth columns of my example code already have the same width... so I don't understand your question.

[salehin]

Hi gmedina

I meant each column of equal width - i think LaTeX does the autosizing of colum/row-width, based on how many stuffs in cells of a col/row - thus making them unequal.

[gmedina]

You can use p{<length>} to explicitly declare a column width. The following code produces a matrix with four columns, each having a width of 1.3cm. For an explanation on some of the commands and constructs used in the format declaration of the array environments, please refer to the documentation of the array package:

Code: Select all

\documentclass[a4paper,12pt, final]{article}
\usepackage[margin=2.54cm,top=2.54cm]{geometry}
\usepackage{hyperref}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{array}

\begin{document}

\[
\begin{array}{c}
  \hspace*{-3pt}%
  \begin{array}{*{4}{>{\centering\arraybackslash$}p{1.3cm}<{$}}}
    1 & k & x & i\\
    \downarrow & \downarrow & \downarrow & \downarrow
  \end{array} \\
  H= \left[%
  \begin{array}{*{4}{>{\centering\arraybackslash$}p{1.3cm}<{$}}}
    1 & 0 & 0 & 0 \\
    0 & 1 & 0 & 0 \\
    0 & 0 & 1 & 0 \\
    0 & 0 & 0 & 1 \\
    1 & 0 & 0 & 0 \\
    0 & \left( 1-\rho \right)  & 0 & 1 \\
    0 & 0 & \rho  & 0%
  \end{array}
  \right]
  \begin{array}{@{\leftarrow\, }c}
    1 \\
    k \\
    x \\
    i \\
    1 \\
    k^{\prime } \\
    x^{\prime }%
  \end{array}
\end{array}
\]

\end{document}

[salehin]

Thank you again for your kind help, gmedina. It is much appreciated.