Re: Using list output (Newbie)

• To: mathgroup at smc.vnet.net
• Subject: [mg37437] Re: Using list output (Newbie)
• From: Liguo Song <liguo.song at vanderbilt.edu>
• Date: Tue, 29 Oct 2002 00:09:40 -0500 (EST)
• Organization: Department of Physics, Vanderbilt University
• References: <ZC2v9.44165\$X9.12902626@twister.socal.rr.com>
• Sender: owner-wri-mathgroup at wolfram.com

```Hi, Mitch,

There might be a better way to do this. But, here comes a method used by
a newbie like me.

Solve will give a list of solutions in form of {{a->1, b->2},
{a->2,b->3}}. This is a list, and you can use the normal way to access
the element of list. Such as A={{a->1, b->2}, {a->2,b->3}}, then A[[1]]
will give you {a->1, b->2}.
And, A[[1]][[1]] will be a->1.

Here a->1 is Rule[a,1], and you can use A[[1]][[1]][[1]] to get "a",
while A[[1]][[1]][[2]] to get "1".

Try to read about the Principles of Mathematica in the Mathematica Book

Good luck.

Liguo (Leo)

Mitch Thompson wrote:

>I am trying to reference the output of a Solve command which provided a list
>of 5 solutions (looks like {a->1, b->2, etc.}).
>
>I would like to extract single answers from this result for use in a
>subsequent calculation.  Any help is appreciated.  Thanks.
>
>
>
>

```

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