gnuplot> b=log10(0.5)
gnuplot> print b
-0.301029995663981
gnuplot> set logscale x 2
gnuplot> set logscale y 10
gnuplot> unset logscale y
gnuplot> b=log10(0.5)
gnuplot> print b
-0.301029995663981
gnuplot> set logscale x 2
gnuplot> set logscale y 10
gnuplot> unset logscale y