From 149b1f7b623ea39bb4a6ebe876ecff9e54416664 Mon Sep 17 00:00:00 2001
From: Lauchmelder <robert.trololo@gmail.com>
Date: Fri, 2 Apr 2021 16:11:19 +0200
Subject: [PATCH] Added kborderstyle.sty
---
kbordermatrix.sty | 151 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 151 insertions(+)
create mode 100644 kbordermatrix.sty
diff --git a/kbordermatrix.sty b/kbordermatrix.sty
new file mode 100644
index 0000000..67d4869
--- /dev/null
+++ b/kbordermatrix.sty
@@ -0,0 +1,151 @@
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{kbordermatrix}[2011/09/21 Bordered matrix with brackets]
+
+% Author: Kim C Border <kcborder@caltech.edu>
+% Date: SuperBowl XXXVII (Go Bucs)
+
+% Revised 2003/09/20
+% to allow flush right option.
+% Revised 2011/09/21
+% at urging of Bruno Calfa (CMU)
+% to coexist with package arydshln
+% by adding \def\@xarraycr ...
+
+% Defines \kbordermatrix along the lines of plain tex's
+% \bordermatrix (which is still available in LaTeX).
+
+% In particular, as with \bordermatrix,
+% 1. It takes the array as an argument. It does not use \begin{}..\end{}.
+% Is this a feature or a bug?
+% 2. The first row is spaced a bit further apart from the rest.
+% 3. The lower (n-1) by (n-1) block is set off by delimiters.
+% 4. There is an invisible bottom row of the same height as the segregated
+% top row that adds to the height of the equation.
+
+% Differences from \bordermatrix:
+% 1. Square brackets are used in place of parentheses.
+% 2. You may use \\ instead of \cr.
+% 3. The line heights agree with LaTeX's line heights for the
+% array environment, and \arraystretch is respected. This means
+% the bottom (n-1) rows align with the rows of an (n-1)-rowed
+% \begin{array}..\end{array} (with or without delimiters).
+% 4. All columns are centered.
+% ** Modified 2003-9-20 to allow flush right option.
+% 5. The first column is spaced a bit further apart from the rest.
+
+
+% Differences from \left\[\begin{array}...\end{array}\right\]
+% 1. It takes the array as an argument. It does not use \begin{}..\end{}.
+% Is this a feature or a bug?
+% 2. Consequently, you cannot use a column specifier (e.g., {l|cr}).
+% 3. Consequently the maximum number of columns is not specified.
+% 4. Vertical rules must be put in each row in a separate column.
+% 5. You can use \hline and \cline.
+
+% At least it works in the cases I have tried, but I offer no guarantees.
+
+
+
+% cf. \bordermatrix p. 361, and \vrulealign p. 392 of The TeXbook
+
+
+
+% Style parameters, they may be redefined according to taste.
+ \newcommand{\kbldelim}{[} % Left delimiter
+ \newcommand{\kbrdelim}{]}% Right delimiter
+
+ \newcommand{\kbrowstyle}{\scriptstyle}% Style applied to first row
+ \newcommand{\kbcolstyle}{\scriptstyle}% Style applied to first column
+
+ \newlength{\kbcolsep} % Extra separation after first border column
+ \newlength{\kbrowsep} % Extra separation after first border row
+
+ \setlength{\kbcolsep}{.5\arraycolsep}
+ \setlength{\kbrowsep}{.2ex}
+
+ \newif\ifkbalignright
+
+% Scratch lengths (to be computed)
+ \newlength{\br@kwd} % Width of delimiter
+ \newlength{\k@bordht} % Height of border column
+
+% This is it
+\newcommand{\kbordermatrix}[1]{%
+\begingroup
+ % \br@kwd depends on font size, so compute it now.
+ \setbox0=\hbox{$\left\kbldelim\right.$}
+ \setlength{\br@kwd}{\wd0}
+ % Compute the array strut based on current value of \arraystretch.
+ \setbox\@arstrutbox\hbox{\vrule
+ \@height\arraystretch\ht\strutbox
+ \@depth\arraystretch\dp\strutbox
+ \@width\z@}
+ % Compute height of first row and extra space.
+ \setlength{\k@bordht}{\kbrowsep}
+ \addtolength{\k@bordht}{\ht\@arstrutbox}
+ \addtolength{\k@bordht}{\dp\@arstrutbox}
+ % turn off mathsurround
+ \m@th
+ % Set the first row style
+ \def\@kbrowstyle{\kbrowstyle}
+ % Swallow the alignment into box0:
+ \setbox0=\vbox{%
+ % Define \cr for first row to include the \kbrowsep
+ % and to reset the row style
+ \def\cr{\crcr\noalign{\kern\kbrowsep
+ \global\let\cr=\endline
+ \global\let\@kbrowstyle=\relax}}
+ % Redefine \\ a la LaTeX:
+ \let\\\@arraycr
+ % The following are needed to make a solid \vrule with no gaps
+ % between the lines.
+ \lineskip\z@skip
+ \baselineskip\z@skip
+ % Compute the length of the skip after the first column
+ \dimen0\kbcolsep \advance\dimen0\br@kwd
+ % Here begins the alignment:
+ \ialign{\tabskip\dimen0 % This space will show up after the first column
+ \kern\arraycolsep\hfil\@arstrut$\kbcolstyle ##$\hfil\kern\arraycolsep&
+ \tabskip\z@skip % Cancel extra space for other columns
+ \kern\arraycolsep\hfil$\@kbrowstyle ##$\ifkbalignright\relax\else\hfil\fi\kern\arraycolsep&&
+ \kern\arraycolsep\hfil$\@kbrowstyle ##$\ifkbalignright\relax\else\hfil\fi\kern\arraycolsep\crcr
+ % That ends the template.
+ % Here is the argument:
+ #1\crcr}% End \ialign
+ }% End \setbox0.
+ % \box0 now holds the array.
+ %
+ % This next line uses \box2 to hold a throwaway
+ % copy of \box0, leaving \box0 intact,
+ % while putting the last row in \box5.
+ \setbox2=\vbox{\unvcopy0 \global\setbox5=\lastbox}
+ % We want the width of the first column,
+ % so we lop off columns until there is only one left.
+ % It's not elegant or efficient, but at 1 gHz, who cares.
+ \loop
+ \setbox2=\hbox{\unhbox5 \unskip \global\setbox3=\lastbox}
+ \ifhbox3
+ \global\setbox5=\box2
+ \global\setbox1=\box3
+ \repeat
+ % \box1 now holds the first column of last row.
+ %
+ % This next line stores the alignment in \box2,
+ % while calculating the proper
+ % delimiter height and placement.
+ \setbox2=\hbox{$\kern\wd1\kern\kbcolsep\kern-\arraycolsep
+ \left\kbldelim
+ \kern-\wd1\kern-\kbcolsep\kern-\br@kwd
+ %
+ % Here is the output. The \vcenter aligns the array with the "math axis."
+ % The negative vertical \kern only shrinks the delimiter's height.
+ % BTW, I didn't find this in the TeXbook,
+ % I had to try various \kerns to see what they did in a
+ % \left[\vcenter{}\right].
+ \vcenter{\kern-\k@bordht\vbox{\unvbox0}}
+ \right\kbrdelim$}
+ \null\vbox{\kern\k@bordht\box2}
+ %
+ \endgroup
+}
+