Re: Do loops in Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg55174] Re: Do loops in Mathematica*From*: dh <dh at metrohm.ch>*Date*: Wed, 16 Mar 2005 05:35:50 -0500 (EST)*References*: <d15s6o$9l2$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, it looks like a bug to me. However,your Do loop is certainly written rather strange. The way to do it (and that works!): Do[p = Solve[x2 + 3*x + 1 == 0, x]; Return[2*p], {i, 1}] Some notes concerning your original Do loop:Do[{p = Solve[x^2 + 3*x + 1 == 0, x], Return[2*p]}, {i, 1}]: The List {..} does not make sense. It does not make sense to multiply a replacement rule by 2: Return[2*p] Daniel dumb_founded wrote: > I am having trouble setting up Do loops in Mathematica. Even when I > put in a return statement, I get no output. Below is a concrete > example of code I am putting in: > > Do[{p = Solve[x^2 + 3*x + 1 == 0, x], Return[2*p]}, {i, 1}] > > > I get nothing out of it. > > Here is a sketch of the code I want to construct but am scared to > because of the above problem I keep encountering. > > (1) the first expression in the Do loop calls the FindRoot function on > nonlinear function of x that involves a constant c. The constant c is > in curly brackets at the end of the Do loop specifying a beginning > value for c and an ending value for c. > (2) I take the root found in the previous expression and I use it to > calculate two numerical integrals > (3) I add or subtract the two numerical integrals found in the previous > expressions and I return the value of this expression (and this > expression alone). > > > I am having a headache figuring out this simple chore. Mathematica > simply refuses to behave. >

**Follow-Ups**:**Re: Re: Do loops in Mathematica***From:*DrBob <drbob@bigfoot.com>