Re: [Ngspice-users] strange error: no such vector

[Holger V. <hol...@un...>]

This is an issue of vectors and plots, global and local availability of 
vectors.

You may have a look at 
https://ngspice.sourceforge.io/ngspice-control-language-tutorial.html#plots 
or at the manual, chapt. 17.3 Plots.

Your simplified netlist probably does not show the root cause (is vector 
'a' residing in plot 'const' (globally available) or generated in 
another plot (then 'a' is local to that specific plot).