Gsyfuy

Does detail obscure or enhance action?

Do infinite dimensional systems make sense?

Languages that we cannot (dis)prove to be Context-Free

Why does Kotter return in Welcome Back Kotter?

How much RAM could one put in a typical 80386 setup?

Roll the carpet

Get value of a counter

Can I ask the recruiters in my resume to put the reason why I am rejected?

Has there ever been an airliner design involving reducing generator load by installing solar panels?

How does one intimidate enemies without having the capacity for violence?

Maximum likelihood parameters deviate from posterior distributions

What's that red-plus icon near a text?

Mutually beneficial digestive system symbiotes

Why is consensus so controversial in Britain?

Which country benefited the most from UN Security Council vetoes?

Was any UN Security Council vote triple-vetoed?

Is it possible to do 50 km distance without any previous training?

What does "Puller Prush Person" mean?

Is it unprofessional to ask if a job posting on GlassDoor is real?

How to format long polynomial?

Why doesn't Newton's third law mean a person bounces back to where they started when they hit the ground?

I'm flying to France today and my passport expires in less than 2 months

Filter any system log file by date or date range

A case of the sniffles

Arithmetic with LuaLaTeX

How to do a 'printline' in LuaTeXLuaTeX: How to handle a Lua function that prints TeX macrosLuaLatex: Difference between `dofile` and `require` when loading lua filesLuaLaTeX issue with string (need to escape)Compilation error with LuaLaTeXCompilation error with LuaLaTeX (texnansi.enc)Compilation sequence with lualatexLuaLatex, includespread and libreoffice table with %Print Latex Code with LuaLatex in functionCompiling classicthesis with LuaLaTexDoes LuaLaTeX mess with pagetotal?Lualatex, deal with pictures in luaConTeXt passing current counter value to lua

1

The function I'm trying to create is one that takes two numbers and prints the result with some math. The following is my code:

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a "$times$" b "$=$" a*c)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

I can't make it print the whole statement correctly. How to solve it?

luatex

share|improve this question

asked 41 mins ago

LevyLevy

427312

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  Try tex.print("$" .. a .. "string\times" .. b .. "=" .. a*b .. "$")
  
  – moewe
  32 mins ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Unlike TeX, to which everything is (by default) a token to be typeset so you can simply write "hello world" and have those words appear in the typeset output, Lua is a general-purpose programming language in which something like a b is a syntax error (assuming a and b are variables). Here, tex.print is a Lua function that takes a single string as input, so you need to give it a single string. (There are other forms of tex.print too, that you can read in the LuaTeX manual, but those are probably not what you want.) Lua uses .. to concatenate strings.
  
  – ShreevatsaR
  25 mins ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  BTW instead of concatenating different strings with .., you can also use string.format to build a string, e.g. in a file test.lua put function prod(a,b) tex.print(string.format([[$%d times %d = %d$]], a, b, a*b)) end and in your file do directlua{dofile('test.lua')} -- here the [[ instead of " is to avoid needing to escape the backslash in times.
  
  – ShreevatsaR
  18 mins ago
  

  
  
  
  

add a comment | 

1

The function I'm trying to create is one that takes two numbers and prints the result with some math. The following is my code:

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a "$times$" b "$=$" a*c)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

I can't make it print the whole statement correctly. How to solve it?

luatex

share|improve this question

asked 41 mins ago

LevyLevy

427312

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  Try tex.print("$" .. a .. "string\times" .. b .. "=" .. a*b .. "$")
  
  – moewe
  32 mins ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Unlike TeX, to which everything is (by default) a token to be typeset so you can simply write "hello world" and have those words appear in the typeset output, Lua is a general-purpose programming language in which something like a b is a syntax error (assuming a and b are variables). Here, tex.print is a Lua function that takes a single string as input, so you need to give it a single string. (There are other forms of tex.print too, that you can read in the LuaTeX manual, but those are probably not what you want.) Lua uses .. to concatenate strings.
  
  – ShreevatsaR
  25 mins ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  BTW instead of concatenating different strings with .., you can also use string.format to build a string, e.g. in a file test.lua put function prod(a,b) tex.print(string.format([[$%d times %d = %d$]], a, b, a*b)) end and in your file do directlua{dofile('test.lua')} -- here the [[ instead of " is to avoid needing to escape the backslash in times.
  
  – ShreevatsaR
  18 mins ago
  

  
  
  
  

add a comment | 

The function I'm trying to create is one that takes two numbers and prints the result with some math. The following is my code:

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a "$times$" b "$=$" a*c)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

I can't make it print the whole statement correctly. How to solve it?

luatex

share|improve this question

asked 41 mins ago

LevyLevy

427312

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a "$times$" b "$=$" a*c)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this question

asked 41 mins ago

LevyLevy

427312

share|improve this question

asked 41 mins ago

LevyLevy

427312

asked 41 mins ago

LevyLevy

427312

asked 41 mins ago

LevyLevy

427312

2 Answers
2

active

oldest

votes

5

documentclass[12pt,a4paper]{article}



directlua{

  function prod(a,b)

    tex.print("$" .. a .. "string\times" .. b .. "=" ..  a*b .. "$")

  end

}



begin{document}    

  The product of 2 and 3: directlua{prod(2,3)}.

end{document}

One tricky thing is getting the backslash escaping game right: LuaTeX: How to handle a Lua function that prints TeX macros. directlua expands macros before passing them on to Lua, so times gets messed up. But something like stringtimes, which should stop that expansion does not quite work as intended because t is a special escape for the tab in Lua. Hence we need to escape the backslash there. In Lua you would have to type \times, but in TeX we need to stop the \ from being expanded, so we need string\times. That is one of the reasons why it is often recommended to use the luacode package or externalise Lua functions into their own .lua files and then load them with dofile or require (see for example How to do a 'printline' in LuaTeX, a bit on dofile and require can be found at LuaLatex: Difference between `dofile` and `require` when loading lua files).

Another thing is that you need .. to concatenate strings.

Finally, you probably want the entire expression in math mode and not just certain bits.

Also moved the directlua function definition into the preamble.

share|improve this answer

edited 24 secs ago

answered 30 mins ago

moewemoewe

96.2k10117360

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  That's what I was looking for. It worked here. Thank you!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  And the explanation was really helpful!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  +1. The only thing I'd change is place the directlua{...} chunk before rather than after begin{document}. That way, it's clearer to the casual reader of the code what's preamble material and what belongs to the body of the document.
  
  – Mico
  2 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Mico Done. Thanks for the idea.
  
  – moewe
  9 secs ago
  

  
  
  
  

add a comment | 

4

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a.. "$string\times$".. b.. "$=$".. a*b)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "85"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2ftex.stackexchange.com%2fquestions%2f483416%2farithmetic-with-lualatex%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

5

documentclass[12pt,a4paper]{article}



directlua{

  function prod(a,b)

    tex.print("$" .. a .. "string\times" .. b .. "=" ..  a*b .. "$")

  end

}



begin{document}    

  The product of 2 and 3: directlua{prod(2,3)}.

end{document}

One tricky thing is getting the backslash escaping game right: LuaTeX: How to handle a Lua function that prints TeX macros. directlua expands macros before passing them on to Lua, so times gets messed up. But something like stringtimes, which should stop that expansion does not quite work as intended because t is a special escape for the tab in Lua. Hence we need to escape the backslash there. In Lua you would have to type \times, but in TeX we need to stop the \ from being expanded, so we need string\times. That is one of the reasons why it is often recommended to use the luacode package or externalise Lua functions into their own .lua files and then load them with dofile or require (see for example How to do a 'printline' in LuaTeX, a bit on dofile and require can be found at LuaLatex: Difference between `dofile` and `require` when loading lua files).

Another thing is that you need .. to concatenate strings.

Finally, you probably want the entire expression in math mode and not just certain bits.

Also moved the directlua function definition into the preamble.

share|improve this answer

edited 24 secs ago

answered 30 mins ago

moewemoewe

96.2k10117360

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  That's what I was looking for. It worked here. Thank you!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  And the explanation was really helpful!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  +1. The only thing I'd change is place the directlua{...} chunk before rather than after begin{document}. That way, it's clearer to the casual reader of the code what's preamble material and what belongs to the body of the document.
  
  – Mico
  2 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Mico Done. Thanks for the idea.
  
  – moewe
  9 secs ago
  

  
  
  
  

add a comment | 

5

documentclass[12pt,a4paper]{article}



directlua{

  function prod(a,b)

    tex.print("$" .. a .. "string\times" .. b .. "=" ..  a*b .. "$")

  end

}



begin{document}    

  The product of 2 and 3: directlua{prod(2,3)}.

end{document}

One tricky thing is getting the backslash escaping game right: LuaTeX: How to handle a Lua function that prints TeX macros. directlua expands macros before passing them on to Lua, so times gets messed up. But something like stringtimes, which should stop that expansion does not quite work as intended because t is a special escape for the tab in Lua. Hence we need to escape the backslash there. In Lua you would have to type \times, but in TeX we need to stop the \ from being expanded, so we need string\times. That is one of the reasons why it is often recommended to use the luacode package or externalise Lua functions into their own .lua files and then load them with dofile or require (see for example How to do a 'printline' in LuaTeX, a bit on dofile and require can be found at LuaLatex: Difference between `dofile` and `require` when loading lua files).

Another thing is that you need .. to concatenate strings.

Finally, you probably want the entire expression in math mode and not just certain bits.

Also moved the directlua function definition into the preamble.

share|improve this answer

edited 24 secs ago

answered 30 mins ago

moewemoewe

96.2k10117360

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  That's what I was looking for. It worked here. Thank you!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  And the explanation was really helpful!
  
  – Levy
  24 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  +1. The only thing I'd change is place the directlua{...} chunk before rather than after begin{document}. That way, it's clearer to the casual reader of the code what's preamble material and what belongs to the body of the document.
  
  – Mico
  2 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Mico Done. Thanks for the idea.
  
  – moewe
  9 secs ago
  

  
  
  
  

add a comment | 

documentclass[12pt,a4paper]{article}



directlua{

  function prod(a,b)

    tex.print("$" .. a .. "string\times" .. b .. "=" ..  a*b .. "$")

  end

}



begin{document}    

  The product of 2 and 3: directlua{prod(2,3)}.

end{document}

One tricky thing is getting the backslash escaping game right: LuaTeX: How to handle a Lua function that prints TeX macros. directlua expands macros before passing them on to Lua, so times gets messed up. But something like stringtimes, which should stop that expansion does not quite work as intended because t is a special escape for the tab in Lua. Hence we need to escape the backslash there. In Lua you would have to type \times, but in TeX we need to stop the \ from being expanded, so we need string\times. That is one of the reasons why it is often recommended to use the luacode package or externalise Lua functions into their own .lua files and then load them with dofile or require (see for example How to do a 'printline' in LuaTeX, a bit on dofile and require can be found at LuaLatex: Difference between `dofile` and `require` when loading lua files).

Another thing is that you need .. to concatenate strings.

Finally, you probably want the entire expression in math mode and not just certain bits.

Also moved the directlua function definition into the preamble.

share|improve this answer

edited 24 secs ago

answered 30 mins ago

moewemoewe

96.2k10117360

documentclass[12pt,a4paper]{article}



directlua{

  function prod(a,b)

    tex.print("$" .. a .. "string\times" .. b .. "=" ..  a*b .. "$")

  end

}



begin{document}    

  The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

edited 24 secs ago

answered 30 mins ago

moewemoewe

96.2k10117360

answered 30 mins ago

moewemoewe

96.2k10117360

answered 30 mins ago

moewemoewe

96.2k10117360

4

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a.. "$string\times$".. b.. "$=$".. a*b)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

add a comment | 

4

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a.. "$string\times$".. b.. "$=$".. a*b)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

add a comment | 

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a.. "$string\times$".. b.. "$=$".. a*b)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

documentclass[12pt,a4paper]{article}



begin{document}

    directlua{

        function prod(a,b)

            tex.print(a.. "$string\times$".. b.. "$=$".. a*b)

        end

    }



    The product of 2 and 3: directlua{prod(2,3)}.

end{document}

share|improve this answer

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692

answered 30 mins ago

Ulrike FischerUlrike Fischer

198k9305692