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Time Narration
00:02 Welcome to the spoken tutorial on creating new commands in LaTeX.
00:08 This tutorial will help the learners to

create or define new commands to get customized output.

redefine the existing commands.

00:18 To follow this tutorial,

1 You should have knowledge of commands that are necessary to create a document in LaTeX. 2 You should also have knowledge of compiling and producing a PDF output in LaTeX. 3 If not, please go through the relevant LaTeX spoken tutorials on this website.

00:37 To record this tutorial, I am using

Ubuntu Linux 14.04 operating system

TeXWorks 0.5

00:47 We all know that commands are special words that are provided to the compiler.
00:52 Commands start with a backslash and sometimes accept parameters.

Example: \noindent, \textbf, \centering

01:02 We can define our own custom commands in LaTeX to save time or for the code to look cleaner.
01:09 Ensure that the custom command you create is not an already existing LaTeX command.
01:15 To define a new command, we write \newcommand{command}{definition} at the beginning of the document.
01:27 Let us open the TeXWorks editor.
01:34 Pause the tutorial at this point.Download and unzip the files provided in the Code Files link below the player.
01:43 You will see some LaTeX code given in the file “newComm.tex” that you downloaded onto your machine.
01:59 We will copy and paste the first block of code from this file into our newly opened tex file.
02:09 Let’s try to understand the program.
02:12 The definition \newcommand{\bbr}{\mathbb R} means that \bbr is the newcommand.
02:24 And when used, it will typeset R in the mathbb font.
02:31 Note that the required packages are loaded in the preamble; in this case \usepackage{amsfonts}
02:40 So, instead of {\mathbb R}, we can use \bbr within dollars while typesetting.
02:48 Let us save the file as newComm.tex
03:00 On compilation, we get the pdf output. Observe the letter R in mathbb font.
03:15 Now, we will see newcommand with parameters.
03:24 It is typically defined as -


03:36 Let’s open a new file in TeXWorks.
03:45 Now switch to our downloaded code file.
03:59 We will copy the next block of code from our downloaded code file and paste it into our new teX file.
04:07 Let us understand the code now.
04:11 We have \newcommand{\bb}[1]{\mathbb {#1}}before the begin document statement.
04:22 Here \bb is the command.

[1] means that the command has one parameter

04:30 \mathbb {#1} defines the command.

#1 means the first parameter.

04:37 Carefully observe the usage after \begin{document}
04:42 We use it within dollars because it contains math symbols.
04:48 \bb followed by the open brace and parameter and again we close the brace.
04:58 We have used it twice with R as the parameter in the first usage and Z as the parameter in the second usage.
05:08 Save the program as newCommP1.tex and compile it.
05:28 In the output, observe that the R and Z are in the mathbb or the blackboard font.
05:40 Next, let’s define a newcommand with 2 parameters.
05:46 Open a new tex file.
06:08 We will copy and paste the next block of code from our downloaded file, as shown here.
06:16 Observe the line \newcommand{\add}[2]{ \left( #1 + #2 \right) } in the document.
06:34 This has been used as $\add{abc}{xyz}$ Here in the definition, \add is the newcommand.
06:47 [2] indicates that it has 2 parameters. {\left( #1+#2\right)} is the definition of the command.
06:57 #1 for the first parameter and #2 for the second parameter.
07:05 #1 and #2 are replaced by the actual text {abc} and {xyz} in this case.
07:16 Let us save as newCommP2.tex and compile the tex file.
07:32 Observe the output.

Here the left and right parenthesis are added and a plus symbol is introduced between the first and second parameters.

07:53 Let’s now learn about the renewcommand.
07:59 renewcommand is used to change or overwrite the existing command.
08:04 The syntax for renewcommand is \renewcommand{command}{definition} It’s quite similar to newcommand.
08:18 Once again, we will open a new tex file.
08:35 We will copy and paste the last block of code from our downloaded file into our newly opened tex file.
08:45 Let us understand the program now.
08:48 The definition \renewcommand{\S}{\mathcal {S}} redefines \S.
08:58 \S normally produces the section symbol (§)
09:02 whereas after redefining \S, produces S in Calligraphic font
09:11 Note that the required package amsmath is preloaded. Also, we use \S within dollar symbols.
09:26 Let us now save the file as renew.tex, compile it and see the output. We can see “S” in calligraphic font.
09:49 Come back to the tex file.
09:59 Note that replacing z for S in the renewcommand does not work.
10:06 This is because there is no existing command defined as \z.
10:12 Please use renewcommand only when you are very sure about what you are doing.
10:26 To summarise, we have learnt


newcommand with parameters


10:37 Assignment

Create a new command \textbfit which will convert the given text into bold and italics.

10:50 The video at the following link summarises the Spoken Tutorial project.

Pls watch it.

10:57 The Spoken Tutorial Project Team : Conducts workshops using spoken tutorials and Gives certificates to those who pass an online test
11:07 For more details, please write to us.
11:11 Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. More information on this Mission is available at this link.
11:24 This is Ambika Vanchinathan signing off. Thanks for joining.

Contributors and Content Editors

Pratik kamble