Re: Defining function with indexed variables
- To: mathgroup at smc.vnet.net
- Subject: [mg99344] Re: Defining function with indexed variables
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Sun, 3 May 2009 05:22:27 -0400 (EDT)
On 5/2/09 at 5:58 AM, phhs80 at gmail.com (Paul Smith) wrote:
>How can one define the function
>f(x1,x2,...,x100) := x1^2 + x2^2 + ... + x100^2
>using superscripts?
It isn't clear to me what you are trying to do here. If I wanted
a function that would compute the sum of squares for an
arbitrary number of arguments I would define it as:
f[x___] := Total[{x}^2]
with this definition I can do
In[10]:= f[3, 4, 5]
Out[10]= 50
In[11]:= f[1, 2]
Out[11]= 5
In[12]:= f[Sequence @@ Range[100]]
Out[12]= 338350
But of course I can get the same result by defining this
function to work on a list. That is
g[x_List]:=Total[x^2]
In[14]:= g[{1, 2}]
Out[14]= 5
In[15]:= g[{3, 4, 5}]
Out[15]= 50
In[16]:= g[Range[100]]
Out[16]= 338350
But neither of these definitions use subscripts. I don't
understand what you mean by "using subscripts" in this case.