Re: Asking PlotRange to take a Dynamic value

*To*: mathgroup at smc.vnet.net*Subject*: [mg97999] Re: Asking PlotRange to take a Dynamic value*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Fri, 27 Mar 2009 05:37:41 -0500 (EST)*References*: <gqfl0o$kra$1@smc.vnet.net>

Hi, what's wrong with Manipulate[ Plot[{Log[x], x^0.2, x^0.25, x^0.3}, {x, 0.01, n}, PlotStyle -> {Red, Blue, Blue, Blue}, PlotRange -> {{1, z}, {0, 55}}], Style["Log[x] vs. \!\(\*SuperscriptBox[\"x\", \"a\"]\) for small \ positive a 0.2, 0.25 & 0.3", 12, Bold], {{z, 10, "x from 1 to "}, {10, 500, 10000, 500000}, PopupMenu}, {n, 0.1, Dynamic[z], Appearance -> "Labeled"}] Regards Jens Andrew wrote: > Hello, > > I apologise in advance for what is probably a stupid question, but I > would appreciate some help in persuading PlotRange to take a Dynamic > value - or suggesting another way to go about things entirely! > > For teaching purposes I wanted to draw a series of graphs of Log[x] > vs. x^a for small positive values of a at different scales (simply to > illustrate how Log[x] is eventually < x^a, for any positive a). I > thought I would use Manipulate to allow students to explore this > interactively. > > E.g for x=0 to 10: > > Manipulate[ > Plot[{Log[x], x^0.2, x^0.25, x^0.3}, {x, 0.001, n}, > PlotStyle -> {Red, Blue, Blue, Blue}, > PlotRange -> {{0, 10}, {0, 3}}], > Style["Log[x] vs. \!\(\*SuperscriptBox[\"x\", \"a\"]\) for small \ > positive a 0.2, 0.25 & 0.3", 12, Bold], > Style["x = 0 to 10", 12, Bold], {n, 0.01, 10, > Appearance -> "Labeled"}] > > & for x=0 to 500,000: > > Manipulate[ > Plot[{Log[x], x^0.2, x^0.25, x^0.3}, {x, 0.001, n}, > PlotStyle -> {Red, Blue, Blue, Blue}, > PlotRange -> {{0, 500000}, {0, 55}}], > Style["Log[x] vs. \!\(\*SuperscriptBox[\"x\", \"a\"]\) for small \ > positive a 0.2, 0.25 & 0.3", 12, Bold], > Style["x = 0 to 500,000", 12, Bold], {n, 0.01, 500000, > Appearance -> "Labeled"}] > > But rather than a series of separate graphs I thought it would be more > elegant to combine them in one plot with a Dynamic value to choose the > scale, e.g.: > > Manipulate[ > Plot[{Log[x], x^0.2, x^0.25, x^0.3}, {x, 0.01, n}, > PlotStyle -> {Red, Blue, Blue, Blue}, > PlotRange -> {{1, Dynamic[z]}, {0, 55}}], > Style["Log[x] vs. \!\(\*SuperscriptBox[\"x\", \"a\"]\) for small \ > positive a 0.2, 0.25 & 0.3", 12, Bold], > Row[{Style["x", Bold], " from 1 to ", > PopupMenu[Dynamic[z], {10, 500, 10000, 500000}]}], {n, 0.1, > Dynamic[z], Appearance -> "Labeled"}] > > Unfortunately, although the graphs will plot, with continually > updating axes, what I really want is to change the plot range for each > value of x & fix it so one can see the curves evolving more easily. I > hope the 2 individual examples above make it clear what I hoped for - > essentially, to click from one to the next with the PopupMenu. The > error message reads (e.g. for x=10): > > Plot::prng: Value of option PlotRange -> {{1,10},{0,55}} is not All, > Full, Automatic, a positive machine number, or an appropriate list of > range specifications. >> > > What's gone wrong? PlotRange -> {{1,10},{0,55}} looks like "an > appropriate list of range specifications" to me! > > Any advice appreciated > > Best regards > > Andrew Graham >