Re: Collect coefficients of array variables during calculation:

*To*: mathgroup at smc.vnet.net*Subject*: [mg87027] Re: Collect coefficients of array variables during calculation:*From*: Peter Pein <petsie at dordos.net>*Date*: Sat, 29 Mar 2008 04:24:36 -0500 (EST)*References*: <fsib0m$5qe$1@smc.vnet.net>

Gopinath Venkatesan schrieb: > Hello Mathematica Friends > > If we have an array variable, and assuming after intermediate calculations, some equations are found to be below. > > eqn1=10. A[[1,1]]+b A[[1,1]]+c A[[1,2]]+3. A[[1,2]] (only for illustration) > > Simplify[] does not combine the coefficients under same array member, i.e. instead of (10.+b)A[[1,1]]+(c+3.)A[[1,2]], it is showing the earlier mentioned form. > > Is there a way to collect them and simplify them. But when I checked for simple cases, Simplify[] seems to work. > > Thanks for the suggestions. > > Regards, > Gopinath > University of Oklahoma > Hi Gopinath, use Collect[] to collect ;-) In[2]:= Collect[eqn1,_Part] Out[2]= (10. + b)*A[[1,1]] + (3. + c)* A[[1,2]] you can give a function as third parameter which is applied to the coefficients: In[3]:= Collect[eqn1, _Part, Rationalize] Out[3]= (10 + b)*A[[1,1]] + (3 + c)*A[[1,2]] hth, Peter