On Oct 14, 2008, at 08:26 , Jason Grout wrote:
>
> William Stein wrote:
>> On Tue, Oct 14, 2008 at 8:07 AM, Marshall Hampton <[EMAIL PROTECTED]
>> > wrote:
>>> I am trying to do a demo for a class and I have encountered a
>>> strange
>>> and very annoying error (or I am missing something).
>>>
>>> If I do:
>>> {{{
>>> var('x,y')
>>> f = (x^2+y^2)^(.5)
>>> cp = contour_plot(f,(-3,3),(-4,4), fill=False, plot_points = 80,
>>> cmap
>>> = 'winter', contours=srange(2.9,3.1,.1))
>>> g = x^2/4+y^2/9-1
>>> gp = implicit_plot(g,(-3,3),(-4,4), plot_points = 80)
>>> pts = point2d([[0,3],[2,0],[-2,0],[0,-3]])
>>> show(cp+gp+pts,figsize = [7*3/4,7])
>>> }}}
>>> then the points with positive coordinates seem misplaced by about
>>> 1/10
>>> of a unit; they should be on the ellipse.
>>>
>>> -M. Hampton
>>
>> If you replace 80 by 500 above then everything looks fine.
>
>
> You took the words right out of my mouth. However, that implicit plot
> comes up as a black ellipse for me (3.1.2 and 3.1.3rc0). I don't
> think
> it should be filled, though, as it should be a plot of x^2/4+y^2/9==1,
> not <=1. Is anyone else seeing that problem?
I see the Black Blot in 3.1.3.rc0 as well.
Justin
--
Justin C. Walker, Curmudgeon at Large
Institute for the Absorption of Federal Funds
-----------
My wife 'n kids 'n dogs are gone,
I can't get Jesus on the phone,
But Ol' Milwaukee's Best is my best friend.
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