RE: Uniquely Subtracting Elements in a Flat List
- To: mathgroup at smc.vnet.net
- Subject: [mg29199] RE: [mg29182] Uniquely Subtracting Elements in a Flat List
- From: "David Park" <djmp at earthlink.net>
- Date: Sat, 2 Jun 2001 17:56:08 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Alan,
Here are two methods.
list = {a, b, c, d};
Drop[list - RotateLeft[list], -1]
{a - b, b - c, c - d}
Table[list[[i]] - list[[i + 1]],
{i, 1, Length[list] - 1}]
{a - b, b - c, c - d}
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
> From: Alan [mailto:kd7cyb at mac.com]
To: mathgroup at smc.vnet.net
>
> I need help taking a flat list, such as {a,b,c,d} and generating another
> list by successively subtracting a-b, b-c, c-d, so that the resulting
> list would be {a-b,b-c,c-d}.
>
> Thanks,
> Alan
>
>