Re: recursively solve equation and save the values only

*To*: mathgroup at smc.vnet.net*Subject*: [mg125793] Re: recursively solve equation and save the values only*From*: Dana DeLouis <dana2010 at me.com>*Date*: Tue, 3 Apr 2012 04:44:25 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

> f = 5.68672 T + 6.46776 T^3 > t = Table[i, {i, 0.2, 3, 0.2}] > sols = Table[Reduce[f == t[[i]], T, Reals], {i, Length[t]}] > ... how to remove the T== , Hi. There are just a few ideas. The Capital T looks like a built-in function, so I changed it to x. f=5.68672 x+6.46776 x^3 sols=Table[Reduce[f==rhs,x,Reals],{rhs,0.2,3,0.2}] [[All,-1]] {0.0351204,0.06995,0.104221,... etc} Others... sols=Flatten[x/.Table[Solve[f==rhs,x,Reals],{rhs,0.2,3,0.2}]] sols=x/.Table[Solve[f==rhs,x,Reals],{rhs,0.2,3,0.2}][[All,-1]] Sometimes for simple items, you may be able to get away with calling Solve/Reduce once. Here, we are assuming (ie caution) that the first solution returns the Real part. equ=(x/.FullSimplify[Solve[a x+b x^3==rhs,x][[1]]]) /. {a->5.68672,b->6.46776}; Table[equ,{rhs,0.2,3,0.2}] {0.0351204, 0.06995, 0.104221,...etc} As a side note, the above let's one do something like this: Plot[equ,{rhs,-50,50},GridLines->Automatic] = = = = = = = = = = HTH :>) Dana DeLouis Mac & Math 8 = = = = = = = = = = On Apr 2, 4:30 am, wyn smjy <wsmjy2... at gmail.com> wrote: > Dear All, > > I am new to Mathematica. I am trying to recursively solve equation and > saving the values into Table. Since I need the real solutions only so > I use Reduce. > > The following is my code: > > f = 5.68672 T + 6.46776 T^3 > > t = Table[i, {i, 0.2, 3, 0.2}] > > sols = Table[Reduce[f == t[[i]], T, Reals], {i, Length[t]}] {T == > 0.0351204, T == 0.06995, T == 0.104221, T == 0.137708, T == 0.170237, > T == 0.201687, T == 0.231988, T == 0.26111, T == 0.289058, T == > 0.315857, T == 0.34155, T == 0.366188, T == 0.389828, T == 0.412529, T > == 0.434347} > > The solution is OK as I compared it to other software as well. The > only thing that matters me is how to remove the T== , i.e. I just need > the solution and then to copy this into another table, say sols2 that > contains > > sols2 = {0.0351204, 0.06995, 0.104221, T == 0.137708,.., 0.434347} > > I tried the following: sols2 = T/.sols but produce the following > error: > > sols2 = ReplaceAll::reps: ... is neither a list of replacement rules > nor a valid dispatch table, and so cannot be used for replacing. >> > > Does anyone know how to remove the T==? > > Thank you, > > Wayan