fill unset readings with 0 instead of nil - else gnuplot gets confused
fill unset readings with 0 instead of nil - else gnuplot gets confused

chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,chr-engwer/Vc,VcDevel/Vc