Re: Changing only Y's in a list of points: How?
- To: mathgroup at smc.vnet.net
- Subject: [mg6728] Re: [mg6665] Changing only Y's in a list of points: How?
- From: Allan Hayes <hay at haystack.demon.co.uk>
- Date: Sat, 12 Apr 1997 02:16:21 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
david at email.labmed.umn.edu (David S. Pieczkiewicz)
[mg6665] Changing only Y's in a list of points: How?
writes
>I have a list of points:
> pointlist = { {x1,y1}, {x2,y2}, {x3,y3}, ..., {xn,yn} };
>.... I'd like to "raise" or "lower" this list, in effect, changing
>all the y's by a constant ...
David:
pointlist = { {x1,y1}, {x2,y2}, {x3,y3}} ;
Transpose[Transpose[ pointlist]+{0,.3}]
{{x1, 0.3 + y1}, {x2, 0.3 + y2}, {x3, 0.3 + y3}}
Or, faster,
Thread[Thread[ pointlist]+{0,.3}]
{{x1, 0.3 + y1}, {x2, 0.3 + y2}, {x3, 0.3 + y3}}
Allan Hayes
hay at haystack.demon.co.uk
http://www.haystack.demon.co.uk