TeX $\times$ symbol not working in matplotlib?

[gwhite]

On Friday, April 18, 2014 9:24:55 AM UTC-7, Chris "Kwpolska" Warrick wrote:
> On Fri, Apr 18, 2014 at 6:18 PM, gwhite <gwhite at ti.com> wrote:
> 
> > I am trying to understand how to get the TeX "\times" symbol to work.  It is in the title() string in the code I pasted in.  The "\circ" symbol seems fine, by comparison.  "\times" ends up as "imes" in the figure title.
> >
> > I am probably doing something dumb (hey, maybe a lot of dumb things!), but if you can spot and describe my mistake, I would be quite happy about that.
> 
> > plt.title('$\mathrm{poles}$ $(\times)$ \
> >            $\mathrm{\&}$ $\mathrm{zeros}$ \
> >            $(\circ)$ $\mathrm{of}$ $T(s)T(-s)$',\ 
> >            fontsize=16)
> 
> You're using a regular string.  In which backspaces can be used in
> escapes.  \t is one of those escapes, it is the tab character.  In
> order to fix, add the letter "r" before the opening quote.  Like this:
>  
> > plt.title(r'$\mathrm{poles}$ $(\times)$ \
> >            $\mathrm{\&}$ $\mathrm{zeros}$ \
> >            $(\circ)$ $\mathrm{of}$ $T(s)T(-s)$',\
> >            fontsize=16)
>
> Moreover, in the next two things, you already did it right in the first place:
> 
> > plt.xlabel(r'$\sigma$', fontsize=16)
> > plt.ylabel(r'$\mathrm{j}\omega$', fontsize=16)


Thanks Chris!  That worked.

I faked myself out since the $(\circ)$ worked *without* the little r prefix. I was blind to it. I guess the difference must be there is no \c thingy to override \circ, so it just does the circle.

Thanks for the note on how the r prefix works. I knew I would screw myself sooner or later on that.

Getting regular text mixed with math text, but with the same font (in regular or italic) is a bit clumsy, I suppose. (I mean getting the spaces in.) At least I can do it. 

I did this too, and it also seems to work:

plt.title(' '.join([r'$\mathrm{poles}$', r'$(\times)$',\
                    r'$\mathrm{\&}$', r'$\mathrm{zeros}$',
                    r'$(\circ)$',  r'$\mathrm{of}$',\
                    r'$T(s)T(-s)$']), fontsize=16)