Opened 2 years ago

Closed 2 years ago

#27717 closed defect (duplicate)

contour_plot raises TypeError: unable to coerce to a real number

Reported by: slabbe Owned by:
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: graphics Keywords:
Cc: vdelecroix Merged in:
Authors: Reviewers: Vincent Delacroix, Sébastien Labbé, Karl-Dieter Crisman
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by slabbe)

As asked here:

​https://ask.sagemath.org/question/46275/typeerror-unable-to-coerce-to-a-real-number/

This works: 

┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 8.8.beta3, Release Date: 2019-04-18               │
│ Using Python 2.7.15. Type "help()" for help.                       │
└────────────────────────────────────────────────────────────────────┘
sage: x=var('x')
sage: y=var('y')
sage: contour_plot(real(x+y*i),(x,-3.1,3.1),(y,-3.1,3.1)) 
Launched png viewer for Graphics object consisting of 1 graphics primitive
sage: contour_plot(imag(x+y*i),(x,-3.1,3.1),(y,-3.1,3.1)) 
Launched png viewer for Graphics object consisting of 1 graphics primitive
sage: contour_plot(abs(x+y),(x,-3.1,3.1),(y,-3.1,3.1)) 
Launched png viewer for Graphics object consisting of 1 graphics primitive

but this does not: 

sage: contour_plot(abs(x+y*i),(x,-3.1,3.1),(y,-3.1,3.1)) 
Traceback (most recent call last):
...
TypeError: unable to coerce to a real number

Change History (7)

comment:1 follow-up: Changed 2 years ago by slabbe

  • Description modified (diff)

As mentionned by Vincent to me, it might be related to #8450. Possibly a duplicate?

Last edited 2 years ago by slabbe (previous) (diff)

comment:2 in reply to: ↑ 1 ; follow-up: Changed 2 years ago by kcrisman

As mentionned by Vincent to me, it might be related to #8450. Possibly a duplicate?

Probably yes.

comment:3 in reply to: ↑ 2 ; follow-up: Changed 2 years ago by vdelecroix

Replying to kcrisman:

As mentionned by Vincent to me, it might be related to #8450. Possibly a duplicate?

Probably yes.

@slabbe: what makes you doubt that it is not a duplicate? #8450 has more plot failure examples, the same reference to the ask question and an explanation of the failure.

comment:4 Changed 2 years ago by kcrisman

  • Reviewers set to Vincent Delacroix, Sébastien Labbé, Karl-Dieter Crisman
  • Status changed from new to needs_review

Let me know if I got any accents wrong.

comment:5 Changed 2 years ago by kcrisman

  • Milestone changed from sage-8.8 to sage-duplicate/invalid/wontfix
  • Status changed from needs_review to positive_review

comment:6 in reply to: ↑ 3 Changed 2 years ago by slabbe

@slabbe: what makes you doubt that it is not a duplicate?

Vincent, what makes you think that I was doubting? It is just that I had 60 emails to read this morning and I did not have time to dig it further. I left the question open for someone (else or me later) to solve the question. Please...

comment:7 Changed 2 years ago by chapoton

  • Resolution set to duplicate
  • Status changed from positive_review to closed
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