# logplot for negative valued function

I would like to plot the following function

Plot[(1/x (0.01/(0.01 + x^2) - (10/(10 + x^2))^2)), {x, 0, 10},
Frame -> True, PlotRange -> All]


which is very peaked at 0.01 in log scale, to show it up to higher values, i.e.:

LogPlot[-(1/x (0.01/(0.01 + x^2) - (10/(10 + x^2))^2)), {x, 0, 100},
Frame -> True, PlotRange -> {10^-9, 10}]


However, since function is negative, I must add a minus sign to the function. I would like to get something like the log plot above, but with the y-axis going downwards and with negative values, looking similar to the plot below

LogPlot[-(1/x (0.01/(0.01 + x^2) - (10/(10 + x^2))^2))^-1, {x, 0, 10},
Frame -> True, PlotRange -> {0.1, 10^3}]


but with the right scaling for log axis and negative value sin stead of positive ones, is it possible?

• Do you require something like the following? f[x_] := (1/x (0.01/(0.01 + x^2) - (10/(10 + x^2))^2)); myTicks = N[Table[{10^i, -10^i}, {i, -9, 1}]]; LogPlot[-f[x], {x, 0, 100}, Frame -> True, PlotRange -> {10^-9, 10}, FrameTicks -> {Automatic, myTicks, None, None}] Mar 21, 2014 at 17:06
• Not, exactly, but I see the solution, because this does the work myTicks = N[Table[{10^-i, -10^i}, {i, -9, 1}]]; LogPlot[- f[x], {x, 0, 100}, Frame -> True, PlotRange -> {10^-9, 10}] LogPlot[-f[x]^-1, {x, 0, 100}, Frame -> True, PlotRange -> {1/10, 10^9}, FrameTicks -> {Automatic, myTicks, None, None}] Mar 21, 2014 at 17:34

myTicks =