Re: Plotting: how does one reverse the time axis tick mark values?

*To*: mathgroup at smc.vnet.net*Subject*: [mg127354] Re: Plotting: how does one reverse the time axis tick mark values?*From*: "djmpark" <djmpark at comcast.net>*Date*: Thu, 19 Jul 2012 03:53:20 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <28693170.5095.1342589825669.JavaMail.root@m06>

The Presentations Application has a CustomTicks function where the first argument IS a 'TickMarkLabelFunction'. Also CustomTicks draws both the major and minor ticks and allows you to control both the style of the ticks and the style of the labels. << Presentations` There are two methods. The first method rescales the displayed tick values of 4 to 0 to go to the underlying plot values of 2 to 6. Then we specify ticks going from 5 to 0 in steps of -1 with 5 minor tick intervals. I used 5 to 0 so the minor ticks would show below the first plot value. xticks = CustomTicks[Rescale[#, {4, 0}, {2, 6}] &, {5, 0, -1, 5}]; ListPlot[Transpose[{Range[6], Range[6]}], Ticks -> {xticks, Automatic}] The second method specifies in terms of the underlying plot values, but uses a number function to rescale the actual display tick values. xticks = CustomTicks[Identity, {1, 6, 1, 5}, CTNumberFunction -> (Rescale[#, {4, 0}, {2, 6}] &)]; ListPlot[Transpose[{Range[6], Range[6]}], Ticks -> {xticks, Automatic}] David Park djmpark at comcast.net http://home.comcast.net/~djmpark/index.html From: James Stein [mailto:james at stein.org] I thought this would be simple, but I am stumped: I wish to display values (on the y axis) for specific times (on the x-axis). Conventionally, time on charts progresses from left to right, and this is my desire. However, I want the ticks along the time axis to be measured in what one might call "countDown units" or "reverse units", for example "Myr before Present" or "Seconds before Midnight" or "Centuries B.C.". As a simple example, consider the result of ListPlot [ Transpose [ { Range [ 6 ] , Range [ 6 ] } ] ] which displays the values 2, 3, 4, 5, 6 along the x axis. My problem is how to construct this same chart, except with values 4, 3, 2, 1, 0 replacing 2, 3, 4, 5, 6. The various ways I tried to do this also mirror-reflect the plotted y-values. I looked for an option called something akin to 'TickMarkLabelFunction', but couldn't find one.