LaTeX/C2/Numbering-Equations/English
| Initialisation: | # Copy numbers.tex into align.tex
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| Opening slide | Welcome to this tutorial on numbering equations using LaTeX
My name is Kannan Moudgalya |
| Learning objectives slide | In this tutorial, we will learn
How to put equation numbers How to remove equation numbers How to correctly reference equations How to use the information on the web |
| System requirements slide | One may use any of Linux, Windows or a Mac operating system
One needs LaTeX I shall use Texworks |
| Prerequisites slide
Press Down arrow
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What are the prerequisites?
One needs to be familiar with spoken tutorials that introduce LaTeX We recommend the use of the Side-by-Side method This information is available at the Spoken Tutorial webpage |
| Additional material slide
Show equation.tex Show ltxprimer pdf file
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I shall use the following files:numbers.tex, which you can see hereltxprimer pdf file from TUG India, it is here
With these files, you will be able to practise along with me If you don't have these files, please download them from the Spoken Tutorial website |
| Open numbers.tex | Let us begin the tutorial |
| Let us learn how to create numbers for equations in LaTeX
I have already opened the file numbers.tex in TeXworks. I have saved it as align.tex to use in this tutorial I will keep the numbers.tex file intact, and not change it Let me open align.tex Please pause the tutorial, make a copy of numbers.tex and open it Whenever you want to start afresh, you can make a new copy of numbers.tex I recommend this method whenever a code file is given with ANY spoken tutorial | |
| Press the typeset key | Let us compile this file by pressing the typeset arrow at the top left hand corner
You can see the pdf file on the right |
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Remove the * from align Compile |
These equations do not have numbers
We can put equation numbers by removing the star from the align star Remove the star from both begin and end statements Forgetting it in the end statement is a common mistake Let’s see what happens if I forget to remove it from the end align statement Let us compile It gives an error message begin align ended with align star Let us remove the star from end align also Let us abort typesetting and compile We now have equation numbers |
| Write a statement that makes use of the number of the second equation | Let us now refer to the second equation in the running text
Put the number 2 after the word equation. Compile We see number 2 in the running text |
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Put \nonumber at the end of first equation and compile
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I will now show you how to remove the equation number of one equation
Suppose that we don’t want a number for the first equation Go to the end of the first equation, but before intertext, and put back slash nonumber Please note that nonumber is one word Do not forget the back slash at the beginning On compiling, the number disappears from the first equation One consequence is that the second equation is now numbered as one |
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Put \label{PID} |
Unfortunately, the reference to the second equation has become wrong in the text
Can we prevent such mistakes even if we have to add or remove equations? Such a requirement occurs frequently while writing reports, theses, papers, etc. It is possible to do this through the label statement We have seen this in a previous tutorial also Let me put \label{PID} at the end of the second equation, but before end align |
| Put \ref{PID} | Replace 2 in the running text with \ref{PID} as I do now
After compiling once, two Question marks appear against the equation number On compiling twice, the question marks get replaced by the correct number |
| Remove \nonumber | Let us change the equation number once again by removing \nonumber
Compile twice to get correct answers |
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Change PID to pid, but don’t compile
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The variable in the ref and label commands have to be identical Check what happens if you change PID in the ref command to lower case
Leave the PID in uppercase in the label command and compile We get question mark here because this lower case pid is not defined I will put pid back in uppercase and compile |
| I will now show you how to take help from the Internet
Before that, I am going to delete everything in the tex file If you don’t like it, you can open a new file | |
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Go to Google page
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To do this part, you need access to Internet
If you don’t have this access now, you may try this part later Let me go to a web browser Let me do a web search on the topic of LaTeX multiline The very first hit is on stackexchange Let me click this “how to align” If you scroll down this page, you will see a question and several answers Most answers present a complete code |
| Copy from top to bottom, not from bottom | Let us copy the code that says 58
This number may be different when you access this page Below that, the pdf output created by this code is shown Let me paste it on the tex file |
| Let us compile the tex file
You can check the output in this pdf file to be identical to what we saw in stackexchange | |
| Please try all commands explained in this web page and understand them | |
| Remove the text between the begin and end document | Next let me delete everything inside the document environment
Let us now open the ltxprimer pdf file that we have provided with this tutorial You can practise this part even if you don’t have web access |
| Let us scroll and go to contents
Let us click “typesetting mathematics” You can see many examples Let us go to page 87 Let us copy “cases code” and paste it within the document environment On compiling it, we get the output given in ltxprimer | |
| You may change equation* to align*, and compile
We get identical results I suggest that you spend a minute in understanding this example I also suggest that you try more examples from ltxprimer | |
| This brings us to the end of this tutorial | |
| What did we learn slide
Press space |
This page summarises what we learnt in this tutorial
Please recall each of these commands This is your first assignment Please do a search on these commands over the web, in ltxprimer, etc. Locate these examples and try them out |
| More assignments slide | I will give some more assignments |
| Assignment 2
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We compiled twice to get correct numbers
Why should we compile twice? Hint: we saw this in an earlier tutorial You can also locate an answer for this in ltxprimer.pdf - search for Cross References |
| Assignment 3 | Try examples from Chapter VIII of ltxprimer pdf file we saw earlier
Try to understand them |
| Assignment 4 | Try multiline examples from the Stackexchange web page we saw earlier |
| About the ST slide
Press the Enter key |
I will now give some general information
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| Workshops slide | We conduct workshops using Spoken Tutorials |
| Answers slide
Press Space key Space Space Space Space twice |
Do you have questions in THIS Spoken Tutorial? * Please visit this site
You will have to register on this website to ask questions |
| Where to post slide | For topics not covered in spoken tutorials, visit stack exchange at this address.
This is a great place to get answers on LaTeX. |
| General questions slide | You may also have questions on our workshops, certificates, etc.
For this, get in touch with us at this email address. |
| Spoken Tutorial project is funded by MHRD, Government of India | |
| Thanks for joining
Goodbye |
