{tex-core} is for questions that are independent of formats and macro packages. Such questions usually relate to low-level TeX programming or the behaviour of TeX at an underlying level. Note that even Plain TeX is a format in itself; for questions about it, use {plain-tex}.

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2
votes
1answer
225 views

Alignment in an enumerate environment using “\hspace” and “\hphantom” commands

I give a display of the first three problems from a multiple-choice test in algebra. The choices in the first problem are displayed using a tabbing environment, and the choices in the second and third ...
4
votes
0answers
122 views

Which algorithms does (La)TeX use? [closed]

People often talk about the many "typesetting wonders" (La)TeX can do because of the countless algorithms it uses. But exactly what are these typesetting algorithms? Concrete examples I have gathered ...
4
votes
1answer
81 views

Declaring array of integers

Is it possible to declare in TeX array of integer numbers ? What I am trying to do is to declare new tabular environment for very long tables spanning accross multiple columns and (or) pages. My ...
1
vote
1answer
112 views

Comma as letter and semicolon as operator in math formulas

Inside document source2e.pdf there are the following two lines \DeclareMathSymbol{,}{\mathpunct}{letters}{"3B} \DeclareMathSymbol{;}{\mathpunct}{operators}{"3B} which treats these two punctuation ...
3
votes
2answers
89 views

Define command to act like \ifvar

I'm trying to manipulate multiple boolean variables which are simply named one, two, three, etc. and since I'm using them with a counter, I have defined some commands to take a numerical input and ...
5
votes
2answers
72 views

How to \show the code of the command \autoref? [duplicate]

Edit: I think this is a duplicate of How can I see the "implementation" of the \LaTeX command? . I wanted to see the code for the hyperref \autoref command, so created this simple document: ...
22
votes
1answer
2k views

formal syntax rules of \dimexpr \numexpr \glueexpr

After looking at various answers on the site and by looking at the documentation of e-tex, I am still wondering what is exactly allowed in the various types of expressions, i.e. \numexpr, \dimexpr and ...
7
votes
2answers
550 views

Is there a complete modern book which explains how a TeX parser works?

Hi I am reading 'The TEXbook' by Donald E. Knuth. But in my point of view is very didactic for people who want to learn TeX. Most of the pages contain exercises. But many things of how a TeX ...
5
votes
3answers
273 views

macro who argument is proxy of next page break or beginning of a new slide

QUESTION: How do I write macros that run a control sequence \C (for example print a figure on the page or slide, a) right after the next page break (or new slide), or b) right before the next page ...
11
votes
1answer
215 views

Detecting the end of line

Minimal working example: \documentclass{article} \usepackage{color} \newcommand{\mytextcolor}[2]{\textbf{1}\textcolor{#1}{#2}\textbf{2}} \begin{document} This is \mytextcolor{red}{red color} rest of ...
53
votes
4answers
12k views

How to check if a macro value is empty or will not create text with plain TeX conditionals?

I have a macro which holds some text value, e.g. \macro{some text}. If it is empty, I would like for nothing to appear in the document, but it has some content of any kind which would produce text ...
1
vote
1answer
45 views

Table changes distance to preceding line depending on rows

This seems to be such a simple issue, but I still have not found an answer to this question. I am using a non-float tabular environment. Depending on how many rows my table has, the distance to the ...
5
votes
1answer
165 views

Segmenting a Bezier curve into equal lengths in tikz/pgf

I'm trying to draw two curves and then create equal sized segments/arcs using pgf/tikz but for some reason the segments are not equally sized. I want to go on and fill each segment with a different ...
12
votes
4answers
453 views

Ratio arithmetic in plain TeX

I would like to calculate the ratio between two dimensions and produce a dimensionless quantity for use in further calculation in the process. I seem to be unable to do so. Specifically, I run into ...
2
votes
0answers
57 views

Where is screed.tex? [closed]

In TeX for the Impatient, Chapter 2, Page 9, it asks to try compiling screed.tex. Where is screed.tex and why did the author not explain what it is?
11
votes
3answers
279 views

Treating the contents of a TeX-style group ({\blah …}) as macro arguments

I am trying to make adjustments to a large document that uses TeX-style macros, like this: {\defun SomeFunctionName arg1 arg2} The \defun macro is defined as \newcommand{\defun}{\tt}. Can I ...
9
votes
3answers
810 views

Detecting \global, \long, \outer, \protected

Is there a way to detect whether or not the next assignment is going to be \global, \long, \outer, or \protected? That is, is it possible to write a command \detectmodifiers such that code like \def\...
43
votes
2answers
2k views

Can you explain how this code works?

I found this code somewhere on the TeX archives and have been puzzling over it for some time. Can anyone describe how it works? % Date: Thu, 7 Feb 91 12:20:50 -0500 %From: amgreene@ATHENA.MIT....
0
votes
0answers
65 views

How to go about learning to program in Tex? [duplicate]

I have been using Tex for a few years now and enjoyed the work of others (e.g., ctan packages, templates, styles). My question sees to practical code to learn from. What would be a good primer, or ...
3
votes
1answer
75 views

TeX expert needed: how to \setto(optimal)width?

there is a problem I have been trying to solve for a while but without success so far. As far as I know, TeX is very good at appropriately breaking text lines with respect to a fixed container width. ...
8
votes
1answer
93 views

Is it possible to adjust the “quantization” of allowable skip lengths?

In plain TeX and derivative formats, the concept of stretchable/shrinkable length, AKA a glue or a skip or a rubber length exists, in general defined as <dimen> plus <stretch-dimen> minus ...
8
votes
5answers
575 views

A more elegant version of the \ifnot macro

A TUGboat article of 15 years ago mentions an \ifnot macro by David Kastrup whose implementation is: \def\ifnot#1{#1\else \expandafter\expandafter\fi \iffalse\iftrue\fi} However, this macro ...
14
votes
2answers
281 views

How can own commands be aware of \global?

When I define a command that defines commands \def\makefoobar{ \def\foo{foo} \def\bar{bar} } and prefix it with \global { \global\makefoobar } it is treated like { \global\def\foo{foo} \...
11
votes
2answers
124 views

split off function for variable as separator

How/Possible to change this implementation of \xSplit so that the separator is a variable filled in at the time of definition (\edef somehow?) or at the actual use of the command?? %based on the ...
9
votes
1answer
532 views

How do counts differ from numexpr

To do basic arithmetic on numbers, one can utilize TeX counts, \newcount\c \c=2 \advance\c 3 \typeout{\the\c} LaTeX counters \newcounter{c} \setcounter{c}{2} \addtocounter{c}{3} \typeout{\thec} ...
1
vote
1answer
92 views

How could I write a Latex tag in source form in section name?

I tried to use \verb|| and \lstinline[language={[LaTeX]TeX}]{} and they failed. I just want to write a name of latex tags in section names for internal purposes. For example, I couldn't compile a ...
38
votes
5answers
6k views

Should I read Donald Knuth's The TeXbook?

I've been using LaTeX for about a year or two as part of writing reports in university and want to gain a more in-depth understanding of how it works (I'm a computer science student). Would Donald ...
8
votes
3answers
308 views

Questions on macro writing in TeX to modify an existing style file: fancybox.sty

I've decided that I must become more adept at TeX if I'm to become proficient with LaTeX. While this is probably obvious to most readers who pass by, my ability to muddle through has hidden this small ...
13
votes
1answer
169 views

Inserting tokens at end of math mode

One can use \everymath and \everydisplay to insert tokens at the beginning of math mode, but what about inserting tokens at end of math mode? Lets say I want to enclose the math mode material in a ...
3
votes
2answers
236 views

Redefining line break (double backslash) for align environment

I am trying to figure out if it is possible to (locally) redefine \\ (double backslash) within amsmath's align environment. On the one hand, I'd like to be able to dynamically insert extra columns, on ...
38
votes
1answer
2k views

What do different \fontdimen<num> mean

I know that \fontdimen<num> returns some dimensions associated with the current font. What are they?
3
votes
1answer
86 views

How to avoid typesetting any cell if a table is empty

Following How can I define a macro that adds a row to a table that has not yet been printed?, I came up with a macro (\AddToTable) that “builds” a table, i.e. appends its argument as the last row of ...
25
votes
5answers
909 views

Most efficient way to reverse a token list (tail recursion)

Goal: reverse a list of characters, going from \def\mylist{abcdefgh} to \def\mylist{hgfedcba}. This is easy using a marker which does not appear in the list, such as \relax: \def\mylist{abcdefgh} \...
8
votes
3answers
139 views

Appending active and expansion sensitive characters to a macro

This question comes up pretty often when people want to build tables with empty columns or similarly building up some active characters inside a macro hoping to expand them at the right time right ...
26
votes
4answers
2k views

Display hyphenation options for a specific word

When TeX produces Overfull box, is puts something like this in the log: Overfull \hbox (15.47195pt too wide) in paragraph at lines 7--9 []\OT1/cmr/m/n/10 I re-ally re-ally want to get dis-played the ...
5
votes
2answers
2k views

how do you put caption on figures in sweave

I have this sweave code. I need to add caption to the figures. I am doing this but it looks like I see the figure before the section{Data ANALYSIS}: \documentclass[letter,12pt]{article} \...
19
votes
2answers
525 views

\expandafter and \aftergroup: where do the 2n+1 and n^2-1 rules come from?

Both TeX primitives \expandafter and \aftergroup have "rules of thumb" stating that \expandafter should be used 2n+1 times to look n tokens ahead (is this correct?). A similar "rule of thumb" holds ...
15
votes
3answers
807 views

How could the macro xii.tex be simplified into a better readable form

I was reading some TeX guides from where I have found this source: \let~\catcode~`76~`A13~`F1~`j00~`P2jdefA71F~`7113jdefPALLF PA''FwPA;;FPAZZFLaLPA//71F71iPAHHFLPAzzFenPASSFthP;A$$FevP A@@...
67
votes
3answers
108k views

Escape character in LaTeX

I need to output the below text but since \ is a special character, I cannot: [RegularExpression(@"\d+")] Also sometimes I need use dollar sign $ as well but it seems to be a special char, too. ...
1
vote
0answers
331 views

Memory overload due to pgfplots / tikz

first of all, I need to mention that there are 2 related threads, that I found usefull: 1, 2. I am working with TeXstudio 2.8.8 on Win 7 64bit (i5 @3.3GHz, 8GB RAM - if this matters). My goal is to ...
1
vote
1answer
276 views

Passing values from PythonTeX to LaTeX

I have read in the PythonTeX manual about how to pass LaTeX values to PythonTeX, but I cannot find any documentation (or a way) to do the reverse. For example, in the LaTeX package datenumber, one ...
3
votes
1answer
83 views

Specifying coordinates with \def in PSTricks

I'm starting with PSTricks. I use the following macro to set cartesian coordinates: \def\newPoint#1(#2,#3) { \expandafter\def\csname x#1\endcsname{#2} \expandafter\def\csname y#1\endcsname{#3}...
20
votes
1answer
401 views

How do I get into XeTeX development?

The support for OpenType fonts has been a great advancement in terms of usability. Unfortunately the microtype package does not offer font expansion for OpenType fonts in XeTeX. I dug a little ...
14
votes
3answers
949 views

How to get the catcode of a token?

For debugging a complicated macro I would like to print out the catcode of a token. Optimally I would like to have a macro \getcatcode such that, for example, \getcatcode{a} would expand to 10. How ...
10
votes
1answer
493 views

What does mathchar do?

The package cmll defines \with (looks like '&') as $ texdef -t latex -p cmll with \with: \mathchar"2026 \the\with: 8230 When I take a look at \& it is defined as texdef -t latex \& ...
1
vote
0answers
151 views

What is the core of TeX as a programming language? [closed]

Tex (and LaTeX) mix programming elements with typesetting ones. It's often confusing to a beginner to tell them apart. Could anyone show me a list of the very core commands of TeX (and perhaps LaTeX) ...
24
votes
7answers
2k views

Are there purely expandable variants of \MakeUppercase?

\MakeUppercase and \uppercase use TeX's uccode, and they are not purely expandable. Say, \edef\temp{\MakeUppercase{abc}} will fail. Sometimes purely expandable macros are very useful. They are ...
4
votes
2answers
332 views

plain TeX error. Undefined control sequence. \pgfutil@

I'm trying to compile the fix mentioned by egreg in this thread: Strange behaviour with PGF/TikZ and Plain TeX output routine Here's the code: \input pgf \catcode`@=11 \newbox\pgfutil@@Output@Box \...
11
votes
1answer
221 views

Why this output using \string on the empty csname

How does this exactly work? \expandafter\string\csname\endcsname I don't know what I would expect to come from there, but definitely not \csname\endcsname_ where _ is a space. I thought \csname<...
12
votes
2answers
312 views

Assertions in Latex

I am writing a long latex document and use many macros for defining mathematical symbols. I would like to ensure that there is no clash in the notation. For example, something like \newcommand{\...