Re: Better Way of Testing and Replacing List Elements?
- To: mathgroup at smc.vnet.net
- Subject: [mg103979] Re: [mg103949] Better Way of Testing and Replacing List Elements?
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Wed, 14 Oct 2009 07:57:00 -0400 (EDT)
- References: <200910140319.XAA22469@smc.vnet.net>
On 14 Oct 2009, at 12:19, careysub wrote: > The code below replaces the negative values in a list with zero, and > is an example of a type of operation I use a lot: > > xxx = {1, 2, 3, 4, 5, -6, -7, 8, 9, 10, -1, 11, 12}; > ReplacePart[xxx, Position[Map[Negative, xxx], True] -> 0] > > Is there a "better" way of doing this (fewer function calls, more > efficient)? > > My feeling is that I'm doing this in an awkward way. > For example: xxx /. _?Negative -> 0 {1,2,3,4,5,0,0,8,9,10,0,11,12} or xxx*UnitStep[xxx] {1,2,3,4,5,0,0,8,9,10,0,11,12} Andrzej Kozlowski
- References:
- Better Way of Testing and Replacing List Elements?
- From: careysub <careysub@gmail.com>
- Better Way of Testing and Replacing List Elements?