Re: How to set y always greater than or equal to x for a function?

*To*: mathgroup at smc.vnet.net*Subject*: [mg46576] Re: How to set y always greater than or equal to x for a function?*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Tue, 24 Feb 2004 21:04:20 -0500 (EST)*Organization*: The University of Western Australia*References*: <c1ehpp$kgg$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <c1ehpp$kgg$1 at smc.vnet.net>, Albert Franco <francoatnsuok at earthlink.net> wrote: > This is an example of one line I would like to calculate in Mathematica: > > Plot3D[Sqrt[y-x],{x,-100,100},{y,-100,100}]; > > How can I best edit this line to make y always greater than or equal to x > during calculation so the program doesn't try to take the square root of a > negative number? << Calculus` Plot3D[Boole[y >= x] Sqrt[y - x], {x, -100, 100}, {y, -100, 100}]; Cheers, Paul -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul