I wonder if it is possible to find an analogical solution for pdflatex instead of latex, see gnuplot in LaTeX, without gnuplottex.
Changing the gnuplot code to:
\begin{gnuplot}[terminal=cairolatex, terminaloptions= pdf input]
set samp 100;
set iso 40;
set xrange [0:1];
set yrange [0:1];
set zrange [0.8:2];
unset key;
unset colorbox;
set hidden3d front;
a = 1;
set xyplane at a;
f(x,y) = (x+y)/(2*sqrt(x*y));
set xlabel "$\\tau_I$";
set ylabel "$\\tau_D$";
set zlabel "$\\zeta$";
set output "figures/cascade.tex"
splot f(x,y) with pm3d at b, f(x,y) with lines;
unset output
\end{gnuplot}
and compiling with pdflatex (-shell-escape is enable) not only the .pdf and .tex files from cairolatex in path figures but also in Tex path root (thesis.tex) thesis-gnuplottex-fig1.gnuplot and thesis-gnuplottex-fig1.tex (0 bytes) are produced. The .gnuplot file can be deleted by writing cleanup in gnuplottex options. Nonetheless, the thesis.pdf document contents the plot, as desired.
If it is possible to define a similar "custom dependency" for pdflatex? May be in the command line of pdflatex?
Thank you for your help in advance.