Re: Plotting symbolic representation of numerica function

*To*: mathgroup at smc.vnet.net*Subject*: [mg54450] Re: [mg54360] Plotting symbolic representation of numerica function*From*: DrBob <drbob at bigfoot.com>*Date*: Sun, 20 Feb 2005 00:11:02 -0500 (EST)*References*: <200502190732.CAA06061@smc.vnet.net>*Reply-to*: drbob at bigfoot.com*Sender*: owner-wri-mathgroup at wolfram.com

Without the functions g1 and g2 and the value x, we're just guessing, but FindRoot is a NUMERICAL solver. Your FindRoot call cannot succeed without values for all three of them. That is, x can't be an undefined symbol, as your plot statement evidently expects it to be. Bobby On Sat, 19 Feb 2005 02:32:07 -0500 (EST), mbekkali <mbekkali at gmail.com> wrote: > Hello. I need to plot solutions to system of equations solved using > numerical functions. I tried: > > {f1[(x_)?NumericQ],f2[(x_)?NumericQ]}:={f1,f2}/.FindRoot[{g1[f1,f2,x]==0,g2[f1,f2,x]==0},{f1,0},{f2,0}][[1]] > Plot[Evaluate[{f1[x],f2[x]},{x,x0,x1}] > > where g1,g2 are some functions and x0,x1 some starting variables. I > get an error message SetDelayed::shape : Lists > {f1[x_?NumericQ],f2[x_?NumericQ]} and {f1,f2} are not the same shape. > I suspect that there is something wrong with SetDelayed because using > Set and Solve plots functions, yet SetDelayed and Solve generates the > same message as SetDelayed and FindRoot. > > I do not understand what is wrong and help file is not useful as it > does not contain examples with SetDelayed for several variables. > > Mukhtar Bekkali > > > > -- DrBob at bigfoot.com www.eclecticdreams.net

**References**:**Plotting symbolic representation of numerica function***From:*"mbekkali" <mbekkali@gmail.com>