Re: plot question

*To*: mathgroup at smc.vnet.net*Subject*: [mg72699] Re: plot question*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Tue, 16 Jan 2007 02:11:10 -0500 (EST)*Organization*: The Open University, Milton Keynes, UK*References*: <eofj7u$hdb$1@smc.vnet.net>

dimitris wrote: > Hello! > > Consider the following graph of the function -ln(|x|). > > Plot[-Log[Abs[x]], {x, -2, 2}, PlotRange -> {Automatic, {-1, 3.5}}, > Axes -> False, Frame -> True, PlotPoints -> 100, FrameLabel -> {"x", > "y"}] > > How is it possible to make the y-axis point downwards (I need this > because in half-space problems within the solid mechanics the possitive > vertical axis is pointed into the half-space)? > > Thanks in advance. > Dimitris > Hi Dimitris, You will find detail explanations from Bob Hanlon and David Park on the following threads "help - how to invert the x or y axis.." at http://groups.google.com/group/comp.soft-sys.math.mathematica/browse_thread/thread/8e1dbacb8a768054/3929283d6a0dacb5?lnk=gst&q=downward+y-axis&rnum=1&hl=en#3929283d6a0dacb5 In your case, the following should work (note that I have also adjusted the plot range accordingly): In[1]:= Plot[Log[Abs[x]], {x, -2, 2}, PlotRange -> {Automatic, {1, -3.5}}, Axes -> False, Frame -> True, PlotPoints -> 100, FrameLabel -> {"x", "y"}, FrameTicks -> {Automatic, Table[{i, -i}, {i, -4, 1}], None, None}]; Regards, Jean-Marc