Re: LogPlot != Plot[Log]

*To*: mathgroup at smc.vnet.net*Subject*: [mg24292] Re: [mg24266] LogPlot != Plot[Log]*From*: "Richard Finley" <rfinley at medicine.umsmed.edu>*Date*: Fri, 7 Jul 2000 00:11:32 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Gy. I believe you set your log plot to a natural log scale compared to LogPlot which is a common log scale....try putting Log[10,C[t]] and {Log[10,10], Log[10,100]} in your g2 definition and now compare g3 with g4....I think you will see they are identical. regards, RF >>> "Gy. Csanady" <csanady at gsf.de> 07/05/00 09:10PM >>> Dear Steve Christensen, I should like to post the following question to the Mathgroup. I am relatively new with Mathematica and I encountered a problem.. Dear MathGroup, I should like to demonstrate some transformation rules graphically using Mathematica extended capabilities. However, the simplest example failed: Let assume a simple exponential function with real parameters: C1[t_] := C0*Exp[-kel*t] param = {C0 -> 100, kel -> 1} we can plot the function easily: g1 = Plot[C1[t] /. param, {t, 0, 2}, PlotRange -> {{0, 2}, {10, 100}}] We can also make a half- logarithmic plot: g2 = Plot[Log[E, C1[t]] /. param, {t, 0, 2}, PlotStyle -> {RGBColor[0, 0, 1], Dashing[{0.05, 0.05}]}, PlotRange -> {{0, 2}, {Log[10], Log[100]}}] In addition we can convert the y-axis to a logarithmic one: g3 = Show[g2, Ticks -> Join[{FullOptions[g2, Ticks][[1]], FullOptions[g2, Ticks][[2]] /. {x_, y_Real, len_, style_} :> {x, Exp[y], len, style}}]] We can obtain a half-logarithmic plot by using the LogPlot function: << Graphics`Graphics` g4 = LogPlot[C1[t] /. param, {t, 0, 2}, PlotRange -> {{0, 2}, {10, 100}}] Now I would expect that plot g4 and g3 become identic: Show[{g3, g4}, PlotRange -> All] But it is not the case. I am sure that there is something wrong. Any help would be appreciated. With best regards Gy. Csanady