Re: To apply a function to a List
- To: mathgroup at smc.vnet.net
- Subject: [mg65638] Re: [mg65597] To apply a function to a List
- From: "David Park" <djmp at earthlink.net>
- Date: Tue, 11 Apr 2006 04:04:52 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Francisco,
Let
testlist = Range[5]
{1, 2, 3, 4, 5}
Then you can either Map f onto the list (see Map in Help)
f /@ testlist
{f[1], f[2], f[3], f[4], f[5]}
or you can set the Attributes of f to Listable (see Attributes in Help) Do
it before defining f if f has a definition.
Attributes[f] = Listable;
f[testlist]
f[1], f[2], f[3], f[4], f[5]}
f[x_] := x^2
f[testlist]
{1, 4, 9, 16, 25}
Here is another function, g, defined as a pure function (look up Function in
Help). It takes the square and subtracts 1.
g = #^2 - 1 &;
g /@ testlist
{0, 3, 8, 15, 24}
In general, you will find the 'functional' programming constructs very
useful.
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Francisco Javier [mailto:pacoga at ctv.es]
To: mathgroup at smc.vnet.net
Dear all,
Let f, l be a function and a list respectively. How can we do
Table[f[list[[n]]],{n,1, Length[list]}]
in another way?
Thanks.
--
----
Francisco Javier García Capitán
http://garciacapitan.auna.com