How to make fonts bigger in **plain tex** math mode? [SOLVED AGAIN]

[Steve Litt]

Thanks Yuri,

Your solution worked, but 12pt was too small. So I found out that the
fontch package works with 8, 10, 12, 14, 20 and 24 points. The only
problem is, inputting \twentyfourpoint in every single math expression
is a bit of an authoring hassle. So I did this:

\def\ma{\twentyfourpoint}

Now I can just put \ma in each, which is reasonably convenient. I've
tested this and it works.

In real life I'll probably use either 14pt or 20pt, or if I need
something in between I'll use Philip's technique with a number instead
of \magstep <number>.

Thanks,

SteveT


Yuri Robbers said on Fri, 28 Apr 2023 10:05:43 +0100

>Hi Steve,
>
>I think the file fontch and - for example - \twelvepoint should do the
>trick for you:
>
>\input fontch
>
>$\forall x \in X, \quad \exists y \leq \epsilon$
>$$\forall x \in X, \quad \exists y \leq \epsilon$$
>
>$\twelvepoint\forall x \in X, \quad \exists y \leq \epsilon$
>$$\twelvepoint\forall x \in X, \quad \exists y \leq \epsilon$$
>
>\bye
>
>> 
>> On 28 Apr 2023, at 09:55, Steve Litt <slitt at troubleshooters.com>
>> wrote:
>> 
>> Thanks Philip,
>> 
>> When I ran your code under luatex, here's what happened:
>> 
>> ===============================================
>> [slitt at mydesk plaintex]$ luatex philip.tex 
>> This is LuaTeX, Version 1.16.0 (TeX Live 2023) 
>> restricted system commands enabled.
>> (./philip.tex
>> ! Font \sevenrm=cmr7  scaled 1440 not loadable: metric data not found
>> or bad. <to be read again> 
>> \relax 
>> l.12 \font\sevenrm=cmr7  scaled \magstep 2
>> 
>> ? 
>> ===============================================
>> 
>> So I know it's handling \magstep 2 correctly because it translates to
>> 1440, but somehow it has trouble finding the metric data (for cmr7, I
>> guess). If I comment out that line, it does the same thing for the
>> cmr10 line. It errors out similarly with pdftex, tex, and luatex.
>> 
>> Thanks,
>> 
>> SteveT
>> 
>> 
>> Philip Taylor (Hellenic Institute) said on Fri, 28 Apr 2023 09:17:13
>> +0100
>>   
>>>> On 28/04/2023 07:47, Steve Litt wrote:
>>>> How do I make fonts bigger in **plain tex** math mode?    
>>> 
>>> Re-define the fonts and font families used in maths mode —
>>> 
>>> $\forall x \in X, \quad \exists y \leq \epsilon$
>>> $$\forall x \in X, \quad \exists y \leq \epsilon$$
>>> 
>>> \font\tenrm=cmr10 scaled \magstep 2
>>> \font\sevenrm=cmr7  scaled \magstep 2
>>> \font\fiverm=cmr5 scaled \magstep 2
>>> \font\teni=cmmi10  scaled \magstep 2
>>> \font\seveni=cmmi7  scaled \magstep 2
>>> \font\fivei=cmmi5 scaled \magstep 2
>>> \font\tensy=cmsy10 scaled \magstep 2
>>> \font\sevensy=cmsy7 scaled \magstep 2
>>> \font\fivesy=cmsy5 scaled \magstep 2
>>> \font\tenex=cmex10 scaled \magstep 2
>>> \font\tenbf=cmbx10  scaled \magstep 2
>>> \font\sevenbf=cmbx7 scaled \magstep 2
>>> \font\fivebf=cmbx5 scaled \magstep 2
>>> \font\tensl=cmsl10  scaled \magstep 2
>>> \font\tentt=cmtt10  scaled \magstep 2
>>> \font\tenit=cmti10  scaled \magstep 2
>>> 
>>> \textfont1=\teni \scriptfont1=\seveni \scriptscriptfont1=\fivei
>>> \textfont2=\tensy \scriptfont2=\sevensy \scriptscriptfont2=\fivesy
>>> \textfont3=\tenex \scriptfont3=\tenex \scriptscriptfont3=\tenex
>>> 
>>> $\forall x \in X, \quad \exists y \leq \epsilon$
>>> $$\forall x \in X, \quad \exists y \leq \epsilon$$
>>> 
>>> \end
>>> 
>>> -- 
>>> /Philip Taylor/
>>>   
>> 
>> 
>> SteveT
>> 
>> Steve Litt 
>> Autumn 2022 featured book: Thriving in Tough Times
>> http://www.troubleshooters.com/bookstore/thrive.htm
>>   


SteveT

Steve Litt 
Autumn 2022 featured book: Thriving in Tough Times
http://www.troubleshooters.com/bookstore/thrive.htm