Q: Symbolic manipulation with Mathematica

*Subject*: [mg3024] Q: Symbolic manipulation with Mathematica*From*: sergio at scisun.sci.ccny.cuny.edu (Sergio Rojas)*Date*: 24 Jan 1996 09:54:12 -0600*Approved*: usenet@wri.com*Distribution*: local*Newsgroups*: wri.mathgroup*Organization*: City College Of New York - Science*Sender*: mj at wri.com

Hi fellows, I would like to know whether is possible to do the following with Mathematica: In[15]:= test = f[x] + x*D[f[x],x] Out[15]= f[x] + x f'[x] In[16]:= test /. f[x]->f[x,y] Out[16]= f[x, y] + x f'[x] However, I would like to get something like: f[x,y] + x*D[f[x,y],x] which then Mathematica can write in the form: (1,0) Out[17]= f[x, y] + x f [x, y] Other manipulation I am trying to do is as follows: In[18]:= y = x/e x Out[18]= - e In[19]:= test = f[x,y] + x*D[f[x,y],x] (0,1) x f [x, -] x e (1,0) x Out[19]= f[x, -] + x (------------ + f [x, -]) e e e If there any way to get this ecuation in the form: (0,1) f [x, y] (1,0) f[x, y] + x (------------ + f [x, y]) e d f[x,y] Finally, is there any way to use the notation: -- dx (1,0) instead of f [x,y] One more thing, is there any special symbol for the Laplacian and Gradient operators in Mathematica.? I'll apreciate any suggestion. rojas E-mail: sergio at scisun.sci.ccny.cuny.edu