Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Setting Negatives to Zero

  • To: mathgroup at smc.vnet.net
  • Subject: [mg82809] Re: Setting Negatives to Zero
  • From: Ray Koopman <koopman at sfu.ca>
  • Date: Wed, 31 Oct 2007 06:18:21 -0500 (EST)
  • References: <fg6qha$dj0$1@smc.vnet.net>

On Oct 30, 1:38 am, "Kevin J. McCann" <Kevin.McC... at umbc.edu> wrote:
> I have a very large data set (64000 x 583) in which negative values
> indicate "no data", unfortunately these negatives are not all the same.
> I would like to efficiently set all these negatives to zero.

With 10% of data missing,  data*UnitStep[data]
is about twice as fast as  data/._?Negative->0
for real data, and about 30 times as fast for integer data.



  • Prev by Date: Re: Parallel computations
  • Next by Date: Re: Easy Mapping problem that has me stumped!
  • Previous by thread: Re: Setting Negatives to Zero
  • Next by thread: Re: Setting Negatives to Zero