Re: DO loop

*To*: mathgroup at smc.vnet.net*Subject*: [mg91298] Re: DO loop*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Thu, 14 Aug 2008 06:59:38 -0400 (EDT)*References*: <g7uo2f$5uj$1@smc.vnet.net>

Hi, since you where not so kind to provide a working example here is one a) define the potential: V[eps_, sigma_][r_] := With[{x = sigma/r}, 4*eps*(x^12 - x^6)] b) compute the radii LJRadii[eps_, sigma_][e_] := Select[r /. Solve[V[eps, sigma][r] == e, r], FreeQ[#, _Complex] && # > 0 &] c) define a integral condition BohrSommerfeld[eps_, sigma_, m_: 1, hbar_: 1][e_, n_Integer] /; e < 0 := Module[{r1, r2, r}, {r1, r2} = LJRadii[eps, sigma][e]; NIntegrate[ Sqrt[2]*Sqrt[m*(hbar*n + (4*eps*sigma^6*(r^6 - sigma^6))/r^12)], {r, r1, r2}] ] d) and now, comes the "DO loop", that compute the function for energy values between [-0.9,-0.01] in steps of 0.0125 BohrSommerfeld[1, 1][#, 0] & /@ Table[e, {e, -0.9, -0.01, 0.0125}] Ooops ! there is no "DO loop", let try a version with out stuff like "&" and "/@" Table[BohrSommerfeld[1, 1][e, 0],{e, -0.9, -0.01, 0.0125}] Now lets make a matrix Table[BohrSommerfeld[1, 1][e, n], {e, -0.9, -0.01, 0.0125}, {n, 0, 4}] and there is again no "DO loop" and I never found out for what a "DO loop" is good for in Mathematica. I had times where I forgot the syntax, that can be found by typing ?Do Regards Jens maria wrote: > Dear all, > > I am new with mathematica and I have the following problem: > I want to repeat a procedure that involves a two main functions for a > precise number of times. Which would be the format of a do loop in > mathematica in order to calculate them and write the results of each > iteration to a matrix? > In order to be more exact I want to solve the following : > > I have a function........ > > Vz[r_]=1/r > intE = EA + e > ........................which I solve and the real solutions are the > intergartion limits at the intergral that follows > Solve[Vz[r] == intE, r] > > olok = NIntegrate[f1[r], {r, Ra, Rb}] // N; > > I would like to repeat this procure for several e values and write a > matrix. > I future I would like to include a second function in the do loop > which is also a function of e. > > Thank you in advance. > > Greetings > Maria >