Re: Forcing Re[]'s to be Real

*To*: mathgroup at smc.vnet.net*Subject*: [mg18268] Re: [mg18223] Forcing Re[]'s to be Real*From*: Haiduke Sarafian <has2 at psu.edu>*Date*: Thu, 24 Jun 1999 14:24:53 -0400*References*: <199906231218.IAA34852@f04n07.cac.psu.edu>*Sender*: owner-wri-mathgroup at wolfram.com

At 03:15 PM 6/23/99 -0700, Anthony Foglia wrote: >On Wed, 23 Jun 1999, Haiduke Sarafian wrote: > >> Anthony; the source of the problem is the argument of k[w] function - It >> should read k[w_]:=... > > Actually I have that correct in my code, but mistyped when I wrote >the message. > >> As you suggested, to extract the Re and Im components of k[w] apply >> Re[ComplexExpand[k[w]] and Im[ComplexExpand[k[w]] - then you can graph the >> outputs. Cheers > > Nope, still can't. Still getting "...not a machine-sized real" >errors. > >--Anthony Anthony; I am surprised with our "Nope" answer!! If you define the k[w] correctly then you can generate two numerical tables one for Re[ComplexExpand[k[w]]] and the other one for Im[...] for a range of w before graph them - this will ensure the graph process. define: r1:=Re[ComplexExpand[[k[w]]] tr1:=N[Table[r1,{w,0,10}] (* this will produce a set of real values *) Plor1=Plot[r1,{w,0,10}]; (* this will plot the r1 function which behaves linearly *) You can try the same procedure for the Im part of the k[w]. I graphed the Re and Im pieces of the k[w] and naturally they worked!! >