plotting findroot

*To*: mathgroup at smc.vnet.net*Subject*: [mg13412] plotting findroot*From*: fanning at leland.stanford.edu (Geoff Fanning)*Date*: Thu, 23 Jul 1998 03:32:57 -0400*Sender*: owner-wri-mathgroup at wolfram.com

I'm trying to plot the results of FindRoot where one parameter changes, but I'm get tons of error messages about not being a length one list of numbers even though I can execute FindRoot w/out error if I specify a single value of the parameter of interest. Often, after a long wait, the plot emerges anyway. Could someone send me some email about what I'm doing wrong, or what I might do to speed up the plotting and get rid of all the error messages that don't seem to be actually producing errors in the end result? TIA, Geoff Plot[t/.FindRoot[(Abs[eigenvalues[[1]]]/.{p->0.0650458,pa->0.00511816})==( Abs[eigenvalues[[2]]]/.{p->0.0650458,pa->0.00511816}),{t, \[Pi]/4-0.05,\[Pi]/4+0.05}],{g,0,0.065}]; FindRoot::"frnum": "Function \!\({\\[LeftSkeleton] 1 \\[RightSkeleton]}\) is not a length \!\ \(1\) list of numbers at \!\(t\) = \!\(0.735398163397448278`\)." ReplaceAll::"reps": "\!\({\\[LeftSkeleton] 1 \\[RightSkeleton]}\) is neither a list of \ replacement rules nor a valid dispatch table, and so cannot be used for \ replacing." FindRoot::"frnum": "Function \!\({\\[LeftSkeleton] 1 \\[RightSkeleton]}\) is not a length \!\ \(1\) list of numbers at \!\(t\) = \!\(0.735398163397448278`\)." FindRoot::"frnum": "Function \!\({\\[LeftSkeleton] 1 \\[RightSkeleton]}\) is not a length \!\ \(1\) list of numbers at \!\(t\) = \!\(0.735398163397448278`\)." General::"stop": "Further output of \!\(FindRoot :: \"frnum\"\) will be suppressed during \ this calculation." ReplaceAll::"reps": "\!\({FindRoot[\(\\[LeftSkeleton] 1 \\[RightSkeleton]\)]}\) is neither a \ list of replacement rules nor a valid dispatch table, and so cannot be used \ for replacing." $Aborted