Re: LogLog plot of NDSolve solution

*To*: mathgroup at smc.vnet.net*Subject*: [mg52598] Re: [mg52557] LogLog plot of NDSolve solution*From*: "David Park" <djmp at earthlink.net>*Date*: Fri, 3 Dec 2004 03:54:28 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Adam, How can you make a LogLog plot over that domain since your function is negative for x < 0.8 (approximately)? The Log of negative numbers gives complex values and Mathematics objects to plotting them. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Adam Getchell [mailto:agetchell at physics.ucdavis.edu] To: mathgroup at smc.vnet.net Hello all, I'm solving an ODE via NDSolve (neutron abundance for Big Bang Nucleosynthesis -- from "Modern Cosmology", S. Dodelson). The result comes out as an InterpolatingFunction, which plots fine using Plot. However, if I wish to do a Log-Log plot, neither LogLogPlot nor LogLogListPlot work. What am I missing? \!\(Dodelson := \(\[CapitalChi]'\)[ x] - \(x\/H\) \(255\/\(\(\[Tau]\_n\) x\^5\)\) \((12 + 6 x + x\^2)\) \((\[ExponentialE]\^\(-x\) - \[CapitalChi][ x] \((1 + \[ExponentialE]\^\(-x\))\))\)\) In[329]:= \!\(\(\(\[IndentingNewLine]\)\(ans = NDSolve[{Dodelson \[Equal] 0 /. {H \[Rule] 1.13, \[Tau]\_n \[Rule] 886.7}, \[CapitalChi][ 1.293] \[Equal] .25}, \[CapitalChi], {x, .1, 1.3}, MaxSteps \[Rule] 10\^6]\)\)\) Using the Evaluate trick suggested by http://www.nhn.ou.edu/~morrison/Mathematica/TipSheets/2Dgraphics.pdf doesn't work. This example doesn't cover LogLogPlots: http://documents.wolfram.com/v4/MainBook/3.8.2.html Other search results on Google haven't turned up anything so far. Thanks, --Adam Getchell