Re: Function interpolation
- To: mathgroup at smc.vnet.net
- Subject: [mg45352] Re: Function interpolation
- From: "Peltio" <peltio at twilight.zone>
- Date: Fri, 2 Jan 2004 04:23:42 -0500 (EST)
- References: <bt0uc8$hec$1@smc.vnet.net>
- Reply-to: "Peltio" <peltioNOSP at Miname.com.invalid>
- Sender: owner-wri-mathgroup at wolfram.com
"Fernando Ronci" wrote >I'm new to Mathematica You could take advantage of the help system. Type ?CommandName to get information on the syntax of the built-in procedures. For example, ?Table will help you finding out how to build tables. Which is not what you need, incidentally. Bear in mind that the main structure in Mathematica is the expression, with a head 'Head' and arguments 'argn' passed to it inside square brackets. Head[arg1,arg2,...] The head and the arguments can be expressions themselves. For example: Sin[x] Derivative[f][x] Table[Sin[x], {x,0,Pi,Pi/30}] Mathematica can be seen as an 'evaluator' that parses every expression passed to it applying user defined and built-in rules until there are no more changes. There are priorities to be obeyed to, and several methods to force or avoid the evaluation (you should definitely do a google search for "Mathematica Tutorial"). A "data structure" that is very widely used in Mathematica is that of List. Lists can be input as expressions with head List or directly by means of curly brackets. The can be nested, of course, to create multidimensional objects. mylist = List[1,2,3,4] mylist = {1,2,3,4} mydata = List[ List[0, 0], List[1, 2], List[2, 4] ] mydata = {{0, 0}, {1, 2}, {2, 4}} In your case all you need to do is to input your data as a list, prior to interpolate it: mydata= {{0, 0}, {1, 2}, {2, 4}, {3, 8}, {4, 16}, {5, 32}} newfunction = Interpolation[%] newfunction[2.3] Of course if you want you can use Table to build up your list of data: mydata= Table[{k, Sign[k] 2^(k-1)}, {k,0,4} ] newfunction = Interpolation[%] newfunction[2.3] cheers, Peltio -- Invalid address in reply-to. Crafty demunging required to mail me.