Re: Question about ColorFunction

*To*: mathgroup at smc.vnet.net*Subject*: [mg126611] Re: Question about ColorFunction*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Thu, 24 May 2012 03:33:04 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201205230729.DAA04974@smc.vnet.net>

On my system the two plots on the bottom row of the Grid below look the same. $Version "8.0 for Mac OS X x86 (64-bit) (October 5, 2011)" With[{is = ImageSize -> 300, cfs = ColorFunctionScaling -> False}, Grid[{ {Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[Sin[#1 + #2]] &), is], Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[#3] &), is]}, {Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[Sin[#1 + #2]] &), cfs, is], Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[#3] &), cfs, is]}}]] I recommend that you use Rescale to understand how the scaling affects the output data = Prepend[Flatten[Table[{ x, y, z = Sin[x + y], xs = Rescale[x, {0, 3}], ys = Rescale[y, {0, 3}], Sin[Pi (xs + ys)], Rescale[z, {-1, 1}]}, {x, 0, 3, .75}, {y, 0, 3, 0.75}], 1], {"x", "y", "z=Sin[x+y]", "xs", "ys", "Sin[Pi(xs+ys)]", "zs"}] // Grid Bob Hanlon On Wed, May 23, 2012 at 9:56 AM, JiHui Lou <ywdr1987 at gmail.com> wrote: > Thx for replying. > But when option ColorFunctionScaling->False is added in both, the plots > are still different if u check them carefully... > As you remind me, "With the usual default setting > ColorFunctionScaling->True, all arguments supplied to func are scaled to > lie in the range 0 to 1." is helpful and inspiring. As a result, I have > tried Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> > (Hue[Sin[Pi (#1 + #2)]] &)] to get the same plot as Plot3D[Sin[x + y], {x= , > 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[#3] &)] produce, but unfortunatel= y > they are still different. > So would u be so kind to help me find a way to make the same plot > as Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[#3] &)] > without using ColorFunction form Hue[#3]& but with other form including #= 1 > and #2 ? > Thx a lot! > > > > > > > > *=C2=A5=BC=AA=BB=D4 *=BE=B4=C9=CF From Jee Lou > > > *Jee Lou* *Student, Major: Physics, Zhejiang Normal University, Jinhua, > P.R.China* > > Tel: (+86) 15958451501 | Email: ywdr1987 at gmail.com > Contact me: [image: Google Talk] ywdr1987 at gmail.com [image: MSN] > ywdr at live.cn [image: QQ] ywdr at qq.com > Reach me by the followings: [image: Facebook]<http://www.facebook.com/y= wdr1987> > [image: Twitter] <https://twitter.com/#!/ywdr1987> [image: Google Plus= ]<https://plus.google.com/101548232068182998139/about> > [image: Blog RSS] <http://xiaochoublog.appspot.com/feed> [image: > Blogger] <http://ywdr.blogspot.com/> [image: Google Reader]<https://www.= google.com/reader/shared/ywdr1987> > [image: Picasa] <https://picasaweb.google.com/ywdr1987> [image: > YouTube] <http://youtube.com/user/ywdr1987> [image: Orkut]<http://www.or= kut.com/Main#Profile?uid=10216865585918422690> > > > > > > On Wed, May 23, 2012 at 9:23 PM, Bob Hanlon <hanlonr357 at gmail.com> wrote: > >> "With the usual default setting ColorFunctionScaling->True, all >> arguments supplied to func are scaled to lie in the range 0 to 1." >> >> In your first example, #1 and #2 are each scaled before being fed to >> Sin[#1 + #2]] & so the argument of the Sin is in the interval {0, 2}. >> In your second example, the argument of Hue[#3] & is in the interval >> {0, 1}. The plots would be identical if you used ColorFunctionScaling >> -> False in each. >> >> >> Bob Hanlon >> >> >> On Wed, May 23, 2012 at 3:29 AM, Jee Lou <ywdr1987 at gmail.com> wrote: >> > Anyone explain to me how ColorFunction works? Why Plot3D[Sin[x + y], >> {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[Sin[#1 + #2]] &)] and >> Plot3D[Sin[x + y], {x, 0, 3}, {y, 0, 3}, ColorFunction -> (Hue[#3] &)] >> return different color distributions? >> > >> > > -- Bob Hanlon

**References**:**Question about ColorFunction***From:*Jee Lou <ywdr1987@gmail.com>