Re: symbols to separate characters in a variable
- To: mathgroup at smc.vnet.net
- Subject: [mg42075] Re: symbols to separate characters in a variable
- From: "Will Self" <wself at msubillings.edu>
- Date: Wed, 18 Jun 2003 02:10:50 -0400 (EDT)
- References: <bcmq5f$ss5$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"cyberdude" <quake_earthNOSPAM at hotmail.com> wrote in message news:bcmq5f$ss5$1 at smc.vnet.net... > Hi, > > In mathematica, I try to separate characters in a variable by '_' but > that seems to be problematic. For example, > > > In[1]:= ab_cd=1 > > Set::patset: Warning: ab_cd in assignment ab_cd = 1 > represents a named pattern; use symbol::tag to represent a message name. > > > In[2]:= ab_cd > > > > ab_cd in In[2] doesn't return 1. It looks like a problem. Can it be > overcome? > > Are there other symbols that can separate characters in a variable to let > the characters look 'not packed closely together'? Thank you in advance. > > > David The underscore is reserved for patterns, and you can't use it in symbols. The tradition in Mathematica is to use long, descriptive names for your objects, using words run together, and capitalize all but the first word. For example numberOfPeanuts totalWeightOfPeanuts You may find this irksome but it really does have advantages. Do not capitalize the first character of your own symbols; in this way you avoid clashing with the name of a built-in symbol. This also tells someone reading your work that these are your own symbols, not built-in symbols. For example, you might have a symbol called numberMultiplier. No problem that Mathematica already has one called NumberMultiplier. There is no conflict, and the reader knows that it is your own symbol. When you are doing fast and furious temporary work, you can create two names: numberOfPeanuts = 800 n := numberOfPeanuts Then you can just type n instead of numberOfPeanuts. Also, because of the delayed assignment (colon-equal) if you change the value of numberOfPeanuts, then n will change too. When you are ready to create a presentable document, you can replace all occurrences of n with numberOfPeanuts. (Careful use of Find and Replace works.)