LaTeX/C3/newcommand-in-LaTeX/English-timed

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 - '\newcommand{\command}[parameters]{definition}
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 newcommand with parameters renewcommand
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