#11842 closed defect (duplicate)
substitute_function doesn't work as expected in many cases — at Version 5
Reported by: | mjo | Owned by: | burcin |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | symbolics | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | Burcin Erocal | |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
I'm working on polynomial interpolation at the moment, and these are starting to hurt. Most of them have workarounds, but there don't seem to be any for the expressions involving derivatives.
I've also tried with subs() and the like, but one step at a time.
from sage.all import * # 1. Fails. x = var('x') f = function('f', x) g = function('g', x) p = f print p.substitute_function(f, g) # Outputs "f(x)" # 2. Fails. x = var('x') f = function('f') g = function('g') p = f(x) print p.substitute_function(f(x), g(x)) # Outputs "f(x)" # 3. Works. x = var('x') f = function('f') g = function('g') p = f(x) print p.substitute_function(f, g) # Outputs "g(x)" # 4. Fails. x = var('x') f = function('f') g = function('g') p = f(1) print p.substitute_function(f(1), g(1)) # Outputs "f(1)" # 5. Works. x = var('x') f = function('f') g = function('g') p = f(1) print p.substitute_function(f, g) # Outputs "g(1)" # 6. Fails. x = var('x') f = function('f', x) g = function('g', x) p = f.diff() print p.substitute_function(f, g) # Outputs "D[0](f)(x)" # 7. Fails. x = var('x') f = function('f', x) g = function('g', x) p = f.diff() print p.substitute_function(f(x), g(x)) # Outputs "D[0](f)(x)" # 8. Works. x = var('x') f = function('f') g = function('g') p = f(x).diff() print p.substitute_function(f, g) # Outputs "D[0](g)(x)" # 9. Fails. x = var('x') f = function('f') g = function('g') p = f(x).diff()(1) print p.substitute_function(f(x).diff(), g(x).diff()) # Outputs "D[0](f)(1)" # 10. Fails. x = var('x') f = function('f') g = function('g') p = f(x).diff()(1) print p.substitute_function(f, g) # Works, prints D[0](g)(1).
Change History (5)
comment:1 Changed 10 years ago by
- Milestone changed from sage-4.8 to sage-duplicate/invalid/wontfix
comment:2 Changed 10 years ago by
- Reviewers set to Burcin Erocal
- Status changed from new to needs_review
comment:3 Changed 10 years ago by
- Status changed from needs_review to positive_review
comment:4 Changed 10 years ago by
- Resolution set to duplicate
- Status changed from positive_review to closed
comment:5 Changed 9 years ago by
- Description modified (diff)
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It looks like I accidentally duped #6480 here.