Re: Condensed syntax

• To: mathgroup at smc.vnet.net
• Subject: [mg113498] Re: Condensed syntax
• From: Leonid Shifrin <lshifr at gmail.com>
• Date: Sun, 31 Oct 2010 02:08:35 -0500 (EST)

```Hi Themis,

you can do this by applying a function to level 1:

ij = {{1, 1}, {1, 2}, {1, 3}, {1, 4}, {2, 1}, {2, 2}, {2, 3}, {2,
4}, {3, 1}, {3, 2}, {3, 3}, {3, 4}, {4, 1}, {4, 2}, {4, 3}, {4, 4}}

In[5]:= Apply[f, ij, 1]

Out[5]= {f[1, 1], f[1, 2], f[1, 3], f[1, 4], f[2, 1], f[2, 2],
f[2, 3], f[2, 4], f[3, 1], f[3, 2], f[3, 3], f[3, 4], f[4, 1],
f[4, 2], f[4, 3], f[4, 4]}

Or, which is the same,

In[6]:= f @@@ ij

Out[6]= {f[1, 1], f[1, 2], f[1, 3], f[1, 4], f[2, 1], f[2, 2],
f[2, 3], f[2, 4], f[3, 1], f[3, 2], f[3, 3], f[3, 4], f[4, 1],
f[4, 2], f[4, 3], f[4, 4]}

Regards,
Leonid

On Sat, Oct 30, 2010 at 12:38 PM, Themis Matsoukas <tmatsoukas at me.com>wrote:

> I have a list of {i,j} values,
>
> ij = Tuples[config, 2]
>
> {{1, 1}, {1, 2}, {1, 3}, {1, 4}, {2, 1}, {2, 2}, {2, 3}, {2, 4}, {3,
>  1}, {3, 2}, {3, 3}, {3, 4}, {4, 1}, {4, 2}, {4, 3}, {4, 4}}
>
> and I want to create a list in which the {i,j} are passed as arguments to a
> function f[x,y], i.e., {f[1,1], f[1,2],..., f[4,4]}. I can do this using the
> two-step process:
>
> g[X_List] := Apply[f, X]
> Map[g, ij]
>
> {f[1, 1], f[1, 2], f[1, 3], f[1, 4], f[2, 1], f[2, 2], f[2, 3],
>  f[2, 4], f[3, 1], f[3, 2], f[3, 3], f[3, 4], f[4, 1], f[4, 2],
>  f[4, 3], f[4, 4]}
>
> Is there a way I can bypass the intermediate function g[x] and produce the
> final list in a single step?
>
> Thanks
>
> Themis
>
>

```

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