Re: change the solution to a differential equation into a user defined function - question.nb (0/1)

*To*: mathgroup at smc.vnet.net*Subject*: [mg15603] Re: change the solution to a differential equation into a user defined function - question.nb (0/1)*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Thu, 28 Jan 1999 04:23:31 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <786u4u$29b@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Young lets stat with Your example: sol=DSolve[y'[x]==x,y[x],x] To make a pattern for the solution we have to do replace y[x] by y[x_] and -> by := so we can write down holdsol=(Hold /@ Flatten[sol/. HoldPattern[Rule[z_,b_]] :> Rule@@ {z /. x-> Pattern[x,Blank[]],b}]) /. Rule ->SetDelayed The result is a list of function definitions enclosed by Hold and you have to decide which solution you want. If there is only one solution you can make type ReleaseHold[ holdsol[[1]] ] and see that you have the defintion for the pattern y[x_] Hope that helps Jens Yong Cai wrote: > > I probably have to apologize for the awkward name for the subject. > > My question is > When I define the same function for y[x] by myself, it is evidently a > pattern where x can be taken in any value. > > Then comes the question: how can we use the solution given in a > differential equation which itself is a function as a function for > later use? > > It seems to be straightforward, but I have looked through the > Mathematica Book and found no clue. Your help will be greatly > appreciated.

**error messages in mathematica**

**Re: change the solution to a differential equation into a user defined function - question.nb (0/1)**

**change the solution to a differential equation into a user defined function - question.nb (0/1)**

**Re: change the solution to a differential equation into a user defined function - question.nb (0/1)**