Re: Oddities of Plot[]
- To: mathgroup at smc.vnet.net
- Subject: [mg51160] Re: [mg51123] Oddities of Plot[]
- From: Tomas Garza <tgarza01 at prodigy.net.mx>
- Date: Wed, 6 Oct 2004 04:35:16 -0400 (EDT)
- References: <200410050837.EAA08407@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Plot has attributes {HoldAll, Protected} (all arguments to a function are to be maintained in an unevaluated form). Try In[1]:= Plot[Evaluate[primitive], {x, 0, 1}]; Tomas Garza Mexico City ----- Original Message ----- From: "Roger Mason" <rmason at esd.mun.ca> To: mathgroup at smc.vnet.net Subject: [mg51160] [mg51123] Oddities of Plot[] > Hello, > > Playing around in Mathematica 4 I came across this oddity: > > In[103]:= > circle = Solve[r^2 == (x - h)^2 + (y - k)^2, y] > Out[103]= > {{y -> k - Sqrt[-h^2 + r^2 + 2 h x - x^2]}, {y -> > k + Sqrt[-h^2 + r^2 + 2 h x - x^2]}} > > In[104]:= > primitivelow = y /. circle[[1]] /. {r -> 1 , h -> 0, k -> 0}; > primitivehigh = y /. circle[[2]] /. {r -> 1 , h -> 0, k -> 0}; > primitive = {primitivehigh, primitivelow} > Out[106]= > {1 - x^2, -1 - x^2} > > I don't see why this fails > > In[107]:= > Plot[primitive, {x, 0, 1}] > Plot::"plnr": "primitive is not a > machine-size real number at x = 4.166666666666666`*^-8." > > while this works > > In[108]:= > Plot[{1 - x^2, -1 - x^2}, {x, 0, 1}] > > Thanks, > > Roger Mason > >
- References:
- Oddities of Plot[]
- From: Roger Mason <rmason@esd.mun.ca>
- Oddities of Plot[]