RE: Re: 1/Trig function - help
- To: mathgroup at smc.vnet.net
- Subject: [mg24277] RE: [mg24261] Re: [mg24248] 1/Trig function - help
- From: Wolf Hartmut <hwolf at debis.com>
- Date: Fri, 7 Jul 2000 00:11:21 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Dear Andrzej, changing the output format is definitely the best way, I think. But then you need not rename Sin to sin nor Cos to cos. It suffices to take the HoldForm of the original functions. This then gives undisturbed calculus and a seemless, clear appearance in print: In[1]:= Unprotect[Csc, Sec]; In[2]:= Format[Csc[x_]] := HoldForm[1/Sin[x]] In[3]:= Format[Sec[x_]] := HoldForm[1/Cos[x]] In[4]:= Protect[Csc, Sec]; In[5]:= D[Tan[x], x] Out[5]= 1 2 (------) Cos[x] In[6]:= % /. x -> 0 Out[6]= 1 In[9]:= 1/Sin[y] Out[9]= 1 ------ Sin[y] In[10]:= % Cos[y] Out[10]= Cot[y] > -----Original Message----- > From: Andrzej Kozlowski [SMTP:andrzej at tuins.ac.jp] To: mathgroup at smc.vnet.net > Sent: Thursday, July 06, 2000 5:11 AM > To: mathgroup at smc.vnet.net > Subject: [mg24261] Re: [mg24248] 1/Trig function - help > > Here is one simple way which may perhaps be satisfactory: > > In[11]:= > Unprotect[Csc, Sec]; > In[12]:= > Format[Csc[x_]] := 1/sin[x]; > In[13]:= > Format[Sec[x_]] := 1/cos[x]; > In[14]:= > Protect[Csc, Sec]; > > > Now, for example: > In[15]:= > D[Tan[x], x] > Out[15]= > 1 2 > (------) > cos[x] > > You can still to comutations in the usual way: > > In[16]:= > % /. x -> 0 > Out[16]= > 1 > > Andrzej > -- > Andrzej Kozlowski > Toyama International University, JAPAN > > For Mathematica related links and resources try: > <http://www.sstreams.com/Mathematica/> > > on 7/5/00 4:22 AM, zhl67 at my-deja.com at zhl67 at my-deja.com wrote: > > > Hello, > > > > For some reason I wish the trigonometric functions to the power of -1 > > not automatically evaluated to some other trig functions. For instance, > > I wish the out put of > > > > In[1]:= Sin[x]^(-1) > > > > remain unchanged or appears as > > > > 1 > > Out[1]:=------- > > Sin[x] > > > > but NOT Csc[x]. Is there any cost efficient way to do this? Adding > > rules to Power function might do(I only wish this feature for certain > > argumentx x), but it slows down the Power function at the same time. > > > > Liu Zhao > > > > > > Sent via Deja.com http://www.deja.com/ > > Before you buy. > > >