gnuplot to display an equation title nicely with Latex, but I would like to avoid producing a tex output for that, that I don't know how to handle

I'm executing a:

gnuplot testGNUPlot.dat -p

with testGNUPlot.dat having this content:

plot [-4:4] [-30:5] -x**2+2*x-3 title '$ -x^2-2x-3 $'

I'm receiving this result, which isn't the expected one:

$ -x^2-2x-3 $ isn't transformed, through Latex near the curve legend to its expected -x²-2x-3 form.
(it's more obvious if I try to display for title: $\sqrt{-x^2-2x-3}$ : the square root symbol will never be translated to its graphical counterpart).

How shall I achieve this?

I would like to avoid a tex output, that is currently leading me to messages like epslatex terminal cannot write to standard output, that I don't know how to manage.

(I only need my windows to display the formula correctly near its violet symbol).

If some tex directives are really needed, can they be managed a way they ensure that the script can still, however :

• execute from a command line
• produce a windows with the curve displayed?

The following works for me with Windows 10 and a MiKTeX installation.

Ingredients:

• cairolatex terminal
• LaTeX installation with pdflatex
• PDF viewer (e.g. SumatraPDF for Windows will automatically show the updated PDF, whereas Acrobat Reader will block gnuplot from (over)writing the PDF file)

Either the path of the pdflatex executable is already in your system path or alternatively you can give the absolute path in the gnuplot command.

• the gnuplot script will create the files SO75712292.tex and SO75712292-inc.pdf
• pdflatex will create the final SO75712292.pdf.

Script:

### create LaTeX formatted output
reset session

set term cairolatex standalone size 10cm,7cm
OUTPUT = "SO75712292.tex"
set output OUTPUT

plot [-4:4] [-30:5] -x**2+2*x-3 title '$ -x^2-2x-3 $'

set output
system(sprintf('pdflatex.exe %s', OUTPUT))
### end of script

Result: (screenshot of SO75712292.pdf from SumatraPDF)