{conditionals} is about macros like \if and \ifx that may execute other macros depending on whether certain conditions are true or not. Popular packages are {etoolbox} and {ifthen}.

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7
votes
1answer
70 views

How to use \ref command in the test block of \ifnum?

Is there a way to use \ref{} inside the test part of \ifnum. The following example runs into an error. \documentclass{article} \begin{document} \begin{table} \caption{ex} \label{tab:ex} ...
4
votes
1answer
97 views

Loop Multi-Contingency using etoolbox

I want to use the etoolbox package to manage some loop contingencies over a counting index. In particular, I'd like to do something different on the first and last times through the loop. Now I can ...
10
votes
3answers
169 views

How to align the conditions in a hierarchical structure?

I know how to align the conditions on the left side of the conditions with either aligned, cases, or array if there is only one level. However, I can't figure out how to do so in a hierarchical ...
3
votes
2answers
245 views

How to write multiple conditions in separate lines in braced equations?

How do I typeset something like, X = 0 if a=1 & b=1 & c= 5 & d=9 ; 0 otherwise, using those huge left braces and specifying each condition in a line (4 conditions in 4 separate lines)?
8
votes
1answer
133 views

Adding some text on a page break

How can one test if certain chunks of text (say, numbered questions in a questionnaire) is split between two pages and add automatically related text ("Continued question NN") on the top of the second ...
5
votes
2answers
93 views

A command which produces index if optional argument is not empty

I would like to define a command which creates an index with a certain name, when i pass the name, and doesn't create any index if there is no name passed. My first idea was to write it like that: ...
2
votes
1answer
42 views

ifthen: Replacing a single character in a fixed environment with a longer string

We use a custom command to highlight system properties: \newcommand{\propDesc}[2]{ \fcolorbox{white}{propbg}{ \begin{minipage}[c]{\textwidth} \vspace{1ex} \textcolor{title}{#1} \\ #2 \vspace{1ex} ...
16
votes
4answers
329 views

Test whether passed parameter is a number (possibly floating point) or dimension

With TikZ using the calc library you can write things along the lines of \node (A) at ($(0,0)!0.75!(1,1)$) {}; or you can write something (rather different) \node (B) at ($(0,0)!2in!(1,1)$) {}; ...
3
votes
1answer
155 views

Numbering in Beamer handout

Consider the following MWE. \documentclass[handout]{beamer} \newcounter{slidenumber} \defbeamertemplate*{footline}{infolines theme frame plus slide}{ \setcounter{slidenumber}{\insertpagenumber}% ...
2
votes
0answers
30 views

Dynamically set if environment should be printed [duplicate]

Is it possible to tell LaTeX whether or not some environments should be printed in the output PDF file? I want to create one version of my document with "extended" examples and another with fewer ...
23
votes
1answer
631 views

Use of \relax after \ifnum … \fi construction

I'm reading Malcolm Clark's A Plain TeX Primer. On page 111 there's an exercise to define a macro that prints the current time. I've reproduced Clark's answer below: \newcount\minleft ...
2
votes
1answer
559 views

Boolean operators: can I use AND, OR in `\ifthenelse`? How?

Can I use AND, OR in \ifthenelse? How, can you show me examples and documents? This would make my life easier.
7
votes
1answer
180 views

Is a page modulo 4?

If I want to test whether a page is odd/even (i.e. modulo 2) then I can use the following: \ifthenelse{\isodd{\thepage}}{}{} What can I do if I want to test whether a page is modulo 4? A minimal ...
13
votes
3answers
370 views

How to compare numbers with decimal point and logical OR operation?

I'm reading five values from external CSV file as [\sone, \stwo, \sthree, \sfour, \sfive]. Sample values could be [55.3, 89.0, 33.5, 40, 0.10]. Question : How to compare number with decimal points. ...
8
votes
1answer
104 views

Compare the height of arguments

I'm trying to define a \newcommand with three arguments. I'd like to: compare the height of these arguments choose the largest height to create frames (with that height) around the arguments. ...
0
votes
2answers
495 views

How to number a conditional equation

I am writing the following syntax to get a conditional equation. But the equation is not numbered. How can I number it? \[ f(x) = \begin{cases} x+7 & \text{if $5< x$}; \\ x^2-3 & \text{if ...
6
votes
2answers
212 views

How to select conditional text?

I've three variable statements : Statement1 = You are Great Student. Statement2 = You are average Student. Statement3 = You Need improvement on list of topics mentioned below. In the report ...
6
votes
4answers
255 views

Is there a better way to check divisibility in LaTeX?

I want to draw a trimmed ruler, for example, from 2.3cm to 3.9cm where the distance between two consecutive marks is 1mm. I have difficulty to efficiently check whether or not the counter is a ...
9
votes
3answers
241 views

What is wrong with \ifnum#1=0.09\relax?

The following code does not compile with the following error message Missing = inserted for \ifnum \documentclass[pstricks,border=4pt]{standalone} \usepackage{multido} ...
2
votes
1answer
95 views

Conditional execution based on style existence (listings)

Is there a way in LaTeX (or e-TeX) to check if a style is defined using the listings package (inside a \lstnewenvironment definition)? I mean something like this: \lstdefinestyle{tmpdefaultstyle}{} ...
11
votes
1answer
540 views

If not DeclareOption

I have some documents using a same custom package. That "header" package loads by default the package fullpage. But I would like to write a new LaTeX document, using the same header, but without ...
2
votes
1answer
89 views

Conditional use of multicol

I'm using the multicol package to get two columns, but sometimes the contents is too wide in a particular column and I was wondering if there is a way to first make sure the contents will fit ...
11
votes
2answers
175 views

How to create a macro “environmentally-dependent”

Yesterday I was reading the etoolbox documentation where there are defined some new document commands such as: \Before<Begin/End>Environment{<envir>}{<code>} % ...
4
votes
1answer
87 views

PSTricks, conditional frame size

Consider the following code: \documentclass{article} \usepackage{pst-eucl} \usepackage{siunitx} % LaTeX 3 syntax \ExplSyntaxOn \cs_new_eq:NN \calc \fp_eval:n \ExplSyntaxOff % constants ...
1
vote
0answers
27 views

Name separators, if condition for same command [duplicate]

I am new to LaTeX, just a Beginner, Basically a perl developer, I have created a .tex file \begin{document} \cont{\iname{\isurname{Name1}\ifname{K. C. G.}}\iname{\isurname{Name11}\ifname{Y. ...
6
votes
2answers
105 views

Separators for author group (IF conditon)

I am new to LaTeX, just a beginner, basically a Perl developer. I have created a LaTeX file \begin{document} \cont{\iname{\isurname{Name1}\ifname{K. C. G.}}\iname{\isurname{Name11}\ifname{Y. ...
3
votes
1answer
102 views

header-footer configuring

Need to start page numbering from the n-th page (in this case 6); used ifthen and fancyhdr packages. So, no dotted lines since page 6 and page 5 is already numbered. \usepackage{ifthen} ...
5
votes
2answers
238 views

Putting Multiline Conditional Equations

I am trying to write two equation like, a=b when a>1 a=c when a=0 One obvious choice is putting all in a tabular construct, as, \begin{tabular}{ll} $a=b$ & \text{when $a\ge 1$}\\ ...
5
votes
1answer
107 views

Any way to set a variable externally?

I just posted a question and can now generate a conditional section in a text: how to make a conditional document feature But to extend and generalize the question, first how could I create a ...
4
votes
2answers
145 views

how to make a conditional document feature

I saw in another question about how to create a condition, of which the best practice recommended was \iftoggle. I want to create a macro that will allow the creation of a teacher's note, a section ...
3
votes
1answer
82 views

`\ifhtlatex` needed for running tex4ht with different code [duplicate]

It is much easier to write my texts in an editor with LaTeX, but often clients ask for a word file. tex4ht does a good job, it produces html from a tex-file, which can be easily used. But there are ...
1
vote
1answer
225 views

Tabu/Longtabu: Conditional Column Definition

I want to create a longtabu table with a conditional number of columns: In development mode, 5 columns should be visiable. In the final version, only the first and the last column should be visible. ...
13
votes
5answers
522 views

Test if the first character of a string is 'a'

Is there an easy way to make a macro returning a string (e.g. 'true') if the string input begins by some fixed character, say 'a' ? I can't figure how to combine the different packages to do this. ...
6
votes
2answers
135 views

Branching construct based on the (babel) language selected

I'd like to keep one of my presentations in German and English and have defined a corresponding boolean variable withifthen and a command to typeset either the German or the English text. Is there ...
4
votes
1answer
225 views

conditional content

I'm writing a document in LaTeX that I want to compile in two different versions, V1 and V2 (with two different formatting specifications). Sometimes I need to insert a bit of content into V1 that ...
5
votes
1answer
57 views

Change Sectional Skip Conditioned on Text Existing or not Before Sectional Division

I have a simple document layout with a main heading for the title, and the possibility of starting the first sectional unit (with a standard \section command) right after the title -- meaning, with no ...
7
votes
3answers
180 views

Defining tabular rows with macros using `\ifnum` leads to `Incomplete \ifnum`

I am trying to define tabular rows using a macro which shall perform an conditional definition of the tabular row according to a given parameter. Please consider the following MWE: ...
14
votes
5answers
275 views

A macro that conditionally disregards the need for one of its arguments

Let's suppose I want to write nested equations that contain a fair few nested parenthetical/delimiter characters, like (), [], {}, ||, and perhaps others. Suppose too that I think these things look ...
9
votes
2answers
92 views

How to expand \ifthenelse so that it can be used in \parshape?

How do I get the following MWE to work: \documentclass{article} \usepackage{xifthen} \usepackage{lipsum} \newboolean{bar} \setboolean{bar}{true} \def\foo{\parshape = 2 ...
5
votes
1answer
63 views

How to “count” some table cells and print the result?

Thanks to an answer from David Carlisle found on this site I managed to code this: \documentclass[a4paper,10pt]{article} \usepackage{colortbl} \usepackage{xcolor} ...
4
votes
3answers
588 views

Misplaced \omit and \multicolumn in \IfEqCase

I have the following code with a command that creates rows for a tabular: \documentclass[letterpaper,10pt]{article} \usepackage[utf8]{inputenc} \usepackage{xstring} \newcommand*{\condrow}[2]{ ...
21
votes
2answers
388 views

Show footnotes on odd pages only

I'm writing my thesis using the scrbook-class. Is it possible to display footnotes only on the odd (right) pages? This should mean that \footnote{something} should be collected on even pages and ...
4
votes
1answer
487 views

Use of the comment package

In a .tex document, I'm using the comment package to produce two different versions (let's say : versionA and versionB) of the document. Each version contains different parts (it could be paragraphs, ...
17
votes
3answers
815 views

Conditionally Remove Brackets

I'm trying to create a command with an optional argument using \newcommand{\Af}[1]{{\mathbf{A}_{(#1)}} where the argument is a number. However, I'd like that if no argument is given the bracket ...
3
votes
1answer
134 views

Are there more to applications of \iftrue and \iffalse?

While reading "TeX for the impatient" on the topics of iftrue and iffalse, I encountered this example, \def\isbigger{\let\bigger=\iftrue} \def\isnotbigger{\let\bigger=\iffalse} \def\test#1#2{\ifnum ...
10
votes
1answer
314 views

XeTeX UNICODE Table

I would like to try to write a minimal XeTeX source that generates a comprehensive UNICODE table, substituting in local fonts as required by the current plane. I made the attached code as an MWE for ...
4
votes
1answer
90 views

Testing for “emptiness” (theoretical consideration)

Consider the following theoretical problem: Sometimes, in LaTeX one wants to do the simple test if a macro is empty, e.g. \def\foo{% This is... \ifx\baz\@empty Sparta! \else a pony farm. \fi } ...
13
votes
1answer
343 views

Create Two PDF versions of Classroom slides from Single LaTeX file: Teacher and Student

Is there a way to create a single document that will process a LaTeX file in two different ways (different preambles) and produce two different outputs. Specifically, I want to produce a set of ...
32
votes
3answers
3k views

Difference between \if and \ifx

I try to understand the subtleties of TeX programming, but it is not always easy. For example, in the following code : \def\first{abc} \def\second{abc} \ifx\first\second OK!\else false \fi I ...
6
votes
1answer
83 views

Conditionals in lstlistings

I am trying to put in some lines of code using the lstlistings-package but the code differs on conditionals. How can I only change some lines depending on the conditional? Assume I have the If: ...