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Re: evaluate f[{x,y,z}] when f[x,y,z] defined

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  • Subject: [mg103411] Re: [mg103383] evaluate f[{x,y,z}] when f[x,y,z] defined
  • From: Leonid Shifrin <lshifr at gmail.com>
  • Date: Sun, 20 Sep 2009 06:24:56 -0400 (EDT)
  • References: <200909190926.FAA22303@smc.vnet.net>

Murray,

use Apply:

In[1] = f@@a

Out[1] = Sqrt[29]


Regards,
Leonid



On Sat, Sep 19, 2009 at 2:26 AM, Murray Eisenberg <murray at math.umass.edu>wrote:

> I ought to know how to do this (simply) but don't, or at least don't
> recall how...
>
> Often I have a function of several variables defined, for example:
>
>   f[x_, y_, z_] := Sqrt[x^2 + y^2 + z^2]
>
> And I have some list of numbers, e.g.:
>
>   a = {4, 3, 2};
>
> How can I evaluate the following...
>
>   f[a]
>
> ... without having to make a separate definition such as
>
>   f[{x_, y_, z_}] := f[x, y,z]
>
> ?
>
> --
> Murray Eisenberg                     murray at math.umass.edu
> Mathematics & Statistics Dept.
> Lederle Graduate Research Tower      phone 413 549-1020 (H)
> University of Massachusetts                413 545-2859 (W)
> 710 North Pleasant Street            fax   413 545-1801
> Amherst, MA 01003-9305
>
>


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