Re: datelistplot - log axis for values

*To*: mathgroup at smc.vnet.net*Subject*: [mg82825] Re: [mg82806] datelistplot - log axis for values*From*: Carl Woll <carlw at wolfram.com>*Date*: Thu, 1 Nov 2007 05:03:16 -0500 (EST)*References*: <200710311116.GAA22567@smc.vnet.net>

sdw wrote: >Hi - > >Does anyone have a clever way to make datelistplot act like loglistplot and create nice log Y axis vs. dates? > >this is not the same as just logging the y variable before plotting - I want the Y axis to show the actual values on a log scale, not the log values on a linear scale > >thanks, > >Steven > > > > One way is to use the internal function used by LogPlot and friends. First, make Mathematica load the .mx file necessary for LogPlot functionality: In[1]:= LogPlot Out[1]= LogPlot Next, let's make some data: data = CountryData["US", {"GDP", All}]; We need to scale the data: scaledata = data; scaledata[[All, -1]] = Log[scaledata[[All, -1]]]; Now, we use the internal function Graphics`LogPlotDump`LogScale (this is why we executed In[1], as this function would be undefined if we hadn't): ticks = Graphics`LogPlotDump`LogScale[Min[scaledata[[All, -1]]], Max[scaledata[[All, -1]]]]; Finally, you are ready to make the DateListPlot: DateListPlot[scaledata, FrameTicks -> {Automatic, ticks, True, None}] <plot snipped> Carl Woll Wolfram Research