Re: Possible bug in Opacity[] with plotting function that uses UnitStep?
- To: mathgroup at smc.vnet.net
- Subject: [mg105615] Re: [mg105593] Possible bug in Opacity[] with plotting function that uses UnitStep?
- From: "David Park" <djmpark at comcast.net>
- Date: Fri, 11 Dec 2009 04:18:59 -0500 (EST)
- References: <21151438.1260440464544.JavaMail.root@n11>
What about: y = -400*UnitStep[x - 100.8] + 8*(x - 63.4)*UnitStep[x - 63.4] -8*(x - 43.2)*UnitStep[x - 43.2] + 221.3 Plot[y, {x, 0, 144}, Filling -> Axis, FillingStyle -> Opacity[0.5, Blue], Frame -> True] Or Plot[y, {x, 0, 144}, Filling -> Axis, FillingStyle -> Directive[Opacity[0.5], Blue], Frame -> True] David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Nasser M. Abbasi [mailto:nma at 12000.org] Version 7 on windows XP sp2. This is really a strange one, it seems like a "bug", but if not, then what is it? I have a function defined with UnitStep[]. I plot it using Plot and using Filling->Axis. The filling works ok across all the plot range even with different FillingStyles for the color. But when I use Opacity[] to change the filling Style more, then only _part_ of the plot is now affected by the Opacity[] and the other part is not. Compare the following 2 plots to see: y = -400*UnitStep[x - 100.8] + 8*(x - 63.4)*UnitStep[x - 63.4] -8*(x - 43.2)*UnitStep[x - 43.2] + 221.3 Plot[y, {x, 0, 144}, Filling -> Axis, FillingStyle -> {Opacity[0.5], Blue}, Frame -> True] Plot[y, {x, 0, 144}, Filling -> Axis, FillingStyle -> Blue, Frame -> True] --Nasser