Re: What is the fastest way to threshold data?

*To*: mathgroup at smc.vnet.net*Subject*: [mg85955] Re: What is the fastest way to threshold data?*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Thu, 28 Feb 2008 02:58:23 -0500 (EST)

On 2/27/08 at 4:24 AM, Kevin.McCann at umbc.edu (Kevin J. McCann) wrote: >I have some 3d data {{x1,y1,z1},{x2,y2,z2},...} and I would like to >set the z-values to zero if they fall below zero. More generally, I >would like to set z to a threshold value if it is at or below a >threshold. This seems as though it should be an easy enough thing to >do, but the only way I have figured out is to parse out the >z-vector, do >mask=((#<thresh&) /@ zdata)/.True->0/.False->1; >then zvector = zvector*mask; >and rebuild the {x,y,z} data. Using the built in function Clip is undoubtedly faster. Clip[zvector,{0, Infinity}] will return the values you want. -- To reply via email subtract one hundred and four