Man pages matching name pdl::graphics::gnuplot in section 3pm:

PDL::Graphics::Gnuplot.3pm.en	debian 10 / libpdl-graphics-gnuplot-perl
PDL::Graphics::Gnuplot.3pm.en	debian 11 / libpdl-graphics-gnuplot-perl
PDL::Graphics::Gnuplot.3pm.en	debian 12 / libpdl-graphics-gnuplot-perl