RE: Applying a list of 2D paramters to a mathematica function
- To: mathgroup at smc.vnet.net
- Subject: [mg68077] RE: [mg68041] Applying a list of 2D paramters to a mathematica function
- From: "David Park" <djmp at earthlink.net>
- Date: Fri, 21 Jul 2006 17:36:34 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Curry,
You want to use Apply, and there is a special construction that will map
Apply to the first level of a list. Check the Help for Apply where you will
find:
f @@@ expr is equivalent to Apply[f, expr, {1}].
So, for your case:
f[x_, y_] := x + y;
indices = {{a, b}, {c, d}, {e, f}};
f @@@ indices
{a + b, c + d, e + f}
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Curry Taylor [mailto:curry at 192.168.0.101]
To: mathgroup at smc.vnet.net
I have (for simplicity) something like this:
f[x_, y_] := x+y;
I want to use this function for a variety of parameters in a list:
indices = {{a,b}, {c,d}, {e,f}, ..}
so that I get
{a+b, c+d, e+f, ..}
Doing the intuitive thing (for me)
f /@ indices
results in
{f[{a, b}], f[{c, d}], f[{e, f}], ..}
but what I want is
{f[a, b], f[c, d], f[e, f], ..}
and that's not what I'm getting. I have tried using Flatten, pure
functions (Slot # and &), different Map functions, nesting at parameters
(like {1} and {2}), and other things but I just can't seem to get what I'm
after. Any help please?
Thank you,
Curry