Opened 12 years ago
Closed 12 years ago
#6002 closed defect (duplicate)
parametric_plot3d appears not to give the correct axes values
Reported by: | wcauchois | Owned by: | was |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | graphics | Keywords: | |
Cc: | mvngu | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | Work issues: | ||
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Alden Walker describes the bug in a sage-support thread:
When I run:
parametric_plot( (cos(t), sqrt(2)*sin(t)) , (t,0,2*pi))
I get a nice 2d parametric plot, with the top of the ellipse clearly hitting close to 1.5 on the y-axis. When I run:
parametric_plot3d( (cos(t), 1 , sqrt(2)*sin(t)), (t,0,2*pi))
The top of the ellipse really looks like it's at z=1, and the whole thing looks a lot like a circle.
Even though the bounding box is reported to be ((-1.0, 1.0, -1.41293...), (1.0, 1.0, 1.41293...))
, jmol labels the axes as (-1, 1), (-1, 1), and (0, 2).
If we construct the curve manually:
var('t') from sage.plot.plot import var_and_list_of_values _, vals = var_and_list_of_values((0, 2*pi), 75) w = [] for t in vals: w.append(map(float, (cos(t), 1, sqrt(2)*sin(t))))
Then notice that while line3d(w)
is still incorrect, line3d(w[0:43])
looks correct -- that is, plotting only part of the graph eliminates the error somehow. Quite curious!
Change History (2)
comment:1 Changed 12 years ago by
- Cc mvngu added
comment:2 Changed 12 years ago by
- Milestone changed from sage-4.1.2 to sage-duplicate/invalid/wontfix
- Resolution set to duplicate
- Status changed from new to closed
Close as duplicate of #6930.
#6930 fixes this.