Re: Collecting like terms after TrigReduce

*To*: mathgroup at smc.vnet.net*Subject*: [mg108967] Re: Collecting like terms after TrigReduce*From*: "Carl K. Woll" <carlw at wolfram.com>*Date*: Thu, 8 Apr 2010 08:03:35 -0400 (EDT)

Try Collect: Collect[a1 + a2 + c1 Cos[wt] + c3 Cos[wt] + c4 Cos[wt] + c2 Cos[2 wt] + c4 Cos[2 wt] + s2 Sin[wt] + s1 Sin[2 wt] + s3 Sin[2 wt], _Sin | _Cos] Carl Woll Wolfram Research On 4/7/2010 3:19 AM, Geico Caveman wrote: > I have a large expression that is expressed (after TrigReduce) as a > series of the form: > > c1*cos(wt) + s1*sin(2wt) + a1+c2*cos(2 wt) + c3* cos(wt) + s2*sin(wt) + > c4*cos(wt) + a2+c4*cos(2wt) + s3 sin(2wt) > > (This is just an illustrative example. The precise number of terms is > larger and the number of each kind, impossible to know ahead of the > calculation.) > > Is there any way (for compactness reasons alone) to force Mathematica > to put this in a standard form: > > (a1+a2) + (c1+c3) cos(wt) + (c2 + c4)cos (2wt) + s2 sin(wt) + (s1+s3) > sin(2wt) ? > > Using Simplify is not an option since that gets rid of the higher > harmonic terms (which I want). > >