Am 16.06.2025 um 20:26 schrieb Artur T.:

As you can see, I tried to apply the handy expression using the sprintf() function. It does _not_ provike an error, but the value of  `a` is printed as `nan`.

Is sprintf() actually supported? If not, I guess an error should be thrown.

Given that the doc says that "literal" gnuplot commands are needed, I'd say it's not officially supported, although obviously it does work to some extent.

One tested workaround would be to use string substitution:

<hansl>

set verbose off nulldata 10 series y = normal() scalar a = 0.98 string sta = sprintf("Some statistics = %.2f", a) gnuplot y --time-series --output=display {set title "@sta";}

</hansl>

Or a plot block with an embedded printf can be used:

<hansl>

set verbose off nulldata 10 series y = normal() scalar a = 0.98 plot y option time-series printf "set title 'Some statistics = %.2f';", a end plot --output=display

</hansl>

Note the inner single quotes here -- but alternatively escaped double quotes like \" can also be used.