MathGroup Archive 2007

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

Search the Archive

Re: Setting Negatives to Zero

data = data /. x_?Negative -> 0

or something like

negToZero[x_?NumericQ] = Sign[x] x
data = negToZero@data


On Tue, 30 Oct 2007 03:26:37 -0500, Kevin J. McCann  
<Kevin.McCann at> 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. I know that
> I will likely be embarrassed when I see how to do it, but I can't seem
> to remember or figure it out. I should emphasize that because of the
> size of the data set, this needs to be done efficiently. Another
> programming language does it as follows:
> 		x(x < 0) = 0;
> Thanks,
> Kevin


DrMajorBob at

  • Prev by Date: ANN: ColorbarPlot
  • Next by Date: Re: Vectors,Norms and assumptions
  • Previous by thread: Re: Setting Negatives to Zero
  • Next by thread: Re: Setting Negatives to Zero