Re: How to copy pattern from one expression to another?
- To: mathgroup at smc.vnet.net
- Subject: [mg45334] Re: How to copy pattern from one expression to another?
- From: drbob at bigfoot.com (Bobby R. Treat)
- Date: Wed, 31 Dec 2003 03:23:40 -0500 (EST)
- References: <bsbn05$lri$1@smc.vnet.net> <bsrhq7$qj7$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Fit is defined only for numeric data, so... assuming that other kinds
of data leads to evaluation of some function "g" which you can define,
here's a solution:
ClearAll[f]
f[x:{{_?NumericQ,
_?NumericQ},
{_?NumericQ,
_?NumericQ}}] :=
Block[{y}, Fit[x, {1, y},
y]]
f[x:{{_?AtomQ, _?AtomQ},
{_?AtomQ, _?AtomQ}}] := g[x]
f[{a__}] := f /@ {a}
Testing:
atom1 = {{a61, y61},
{a62, y62}};
atom2 = {{1, 2}, {3, 4}};
xx = {atom1, atom2};
f[atom1]
f[atom2]
f[xx]
f[{atom1, xx, atom2}]
g[{{a61, y61}, {a62, y62}}]
0.9999999999999988 +
1.0000000000000002*y
{g[{{a61, y61}, {a62, y62}}],
0.9999999999999988 +
1.0000000000000002*y}
{g[{{a61, y61}, {a62, y62}}],
{g[{{a61, y61}, {a62,
y62}}],
0.9999999999999988 +
1.0000000000000002*y},
0.9999999999999988 +
1.0000000000000002*y}
Bobby
"Nico" <pipponep at hotmail.com> wrote in message news:<bsrhq7$qj7$1 at smc.vnet.net>...
> Thanks you all for your replies.
> Indeed, what you suggested only solves my partially my issue. I guess I
> should get deeped into the problem...
> Each xi I wrote in the previous messages represents of couple of (x,y)
> coordinates in the form {{a1,y1},{a2,y2}} which represents the points to
> which I have to apply function Fit[].
>
> I.e. xx={{x11,x12,x13},x2,x3,x4,{x51,x52},x6,{x71,x72},x8}=
> {...,{{a61,y61},{a62,y62}},...}
>
> Now, if I set Fit[] to Listable, then I would get
>
> Fit[xx,{1,x},x]={...,{{Fit[a61,{1,x},x],Fit[y61,{1,x},x]},{Fit[a62,{1,x},x],
> Fit[y62,{1,x},x]}},...}
>
> which obviously something meaningless.
> I would therefore need something that "flattens" xx down to a list so that
> only tokens like {{a1,y1},{a2,y2}} appear. I would then apply Fit[] in the
> correct way, and then I would like to construct a list with the same pattern
> that xx had...
> Is it confusing? It is to me...
>
> Please, let me know if you need further explanations. Thanks you all for
> your help!
> Nicola