
Re: Define function using lists or tables
Posted:
Jul 3, 2013 6:06 PM


On 7/3/2013 3:49 AM, Joaquim Nogueira wrote: > Hello. Possibly this is a very simple question. > > Is there a way to define a function over a (BIG) list of ordered pairs? I mean, >suppose that I have a list, created using a Table command or something like that, >of the form [{a,b},{c,d},etc.] such that, after naming it f, say, >f = [{a,b},{c,d},etc.], then, afterwards, whenever there is a command such >that one needs to compute f[a] (or f[c]), the program immediately replaces f[a] by b,and f[c] by d? > > Thank you. >
This looks like a hash table. In Mathematica, it is build in. All what you have to do is:
 f[a] = b; f[c] = d; 
Now
 In[294]:= f[a] Out[294]= b 
There are more advanced ways to do this for more complicated setups.
google the subject of hash tables with mathematica for more information.
Nasser

