Re: treatment on C[i]

*To*: mathgroup at smc.vnet.net*Subject*: [mg100321] Re: treatment on C[i]*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Mon, 1 Jun 2009 07:06:21 -0400 (EDT)*References*: <gvtmfq$get$1@smc.vnet.net>

Hi, it is a question of mathematics, how many free constants you have. For example: DSolve[x''[t] + x[t] == 0, x[t], t] has two free constants, because it is a differential equation of second order and no initial conditions are given. So, look onto your problem and you will know how many free constants you have. And sol = DSolve[x''[t] + x[t] == 0, x[t], t]; Cases[sol, C[_], Infinity] // Union work fine to extract the parameters Regards Jens olfa wrote: > Hi mathematica community, > C[i] is the default form for the i th parameter or constant generated > by mathematica in representing the results of various symbolic > computations in such functions as DSolve, RSolve and Reduce. > My question is: is it possible to know in advance how many C[i] will > be generated? > If not how to represent the generic form of them: For example I have > an input with reduce and mathematica generates in the output C[1],C > [2],C[3] and C[4] so four C[i] in the solutions but before that when I > wrote the input I did not know that it will generate four C[i] and I > need to use something in the input that represent C[i] in general > without knowing how many of them will be generated? I have tried to > use the pattern object _ like that C[ _ ] but it does not work. > > Any suggestion? > Thank you very much. >