Re: multiple outputs from a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg52771] Re: multiple outputs from a function*From*: "Dr. Wolfgang Hintze" <weh at snafu.de>*Date*: Mon, 13 Dec 2004 04:22:12 -0500 (EST)*References*: <cpekeh$744$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Ben, just put the output in a list. Here's an example which gives the first three powers of a variale x Definition In[9]:= pow[x_] := {x, x^2, x^3} Execution In[10]:= y = pow[8] Result Out[10]= {8, 64, 512} The specific components of the list can then be extracted one by one using Part, or [[]]. Example: the second value is In[13]:= y[[2]] Out[13]= 64 Hope this helps, Wolfgang Ben Barrowes wrote: > I feel I must be missing something fundamental... > > How do you write a function (or ?) in Mathematica which produces more > than one output? > > Let's say I have some data and I want a single function to calculate the > mean, variance, std, etc, more than one thing and return those? I know > that there are builtin functions for those parameters, but the point is > I want to define functions with more than one output. > > The only examples I can find are along the lines of: > > f[x_,y_]:=x^2+y^2; > > which have only a single result. > > Is there a different structure altogether, such as a Subroutine, which > allows multiple results from a single subunit? > > One thought I had was that because Mathematica treats everything as > global unless defined specifically local (e.g. in a module), that > variables used in a procedure would be accessible and would thus be a > "result", but it seems scoping problems would arise if this was used too > often. For example: > > In[67]:= > t1[x_,y_]:=(a1=x^2+y;a2=x+y^2;x+y) > > In[68]:= > t2=t1[5,6] > > Out[68]= > 11 > > In[69]:= > a1 > > Out[69]= > 31 > > In[70]:= > a2 > > Out[70]= > 41 > > Is this the accepted method for extracting multiple results from one > function definition? > > > Ben Barrowes > >