Opened 6 years ago
Last modified 4 years ago
#12733 needs_work defect
norm of symbolic matrices gives an error
Reported by: | jason | Owned by: | jason, was |
---|---|---|---|
Priority: | major | Milestone: | sage-6.4 |
Component: | linear algebra | Keywords: | matrix, symbolic |
Cc: | rbeezer, mmasdeu | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | incorrect tests |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
This was reported on ask.sagemath.org: http://ask.sagemath.org/question/1244/symbolic-vector-norm
Here is an example
sage: matrix(SR,[[x]]).norm() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /Users/grout/<ipython console> in <module>() /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/matrix/matrix2.so in sage.matrix.matrix2.Matrix.norm (sage/matrix/matrix2.c:47759)() /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/matrix/matrix0.so in sage.matrix.matrix0.Matrix.change_ring (sage/matrix/matrix0.c:8151)() /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/matrix/matrix_space.pyc in __call__(self, entries, coerce, copy, rows) 554 return self(entries.matrix(), copy=False) 555 --> 556 return self.matrix(entries, copy=copy, coerce=coerce, rows=rows) 557 558 def change_ring(self, R): /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/matrix/matrix_space.pyc in matrix(self, x, coerce, copy, rows) 1403 x = new_x 1404 copy = False -> 1405 return self.__matrix_class(self, entries=x, copy=copy, coerce=coerce) 1406 1407 def matrix_space(self, nrows=None, ncols=None, sparse=False): /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/matrix/matrix_double_dense.so in sage.matrix.matrix_double_dense.Matrix_double_dense.__init__ (sage/matrix/matrix_double_dense.c:3215)() /Users/grout/sage-trees/sage-5.0.beta6/local/lib/python2.7/site-packages/sage/symbolic/expression.so in sage.symbolic.expression.Expression.__complex__ (sage/symbolic/expression.cpp:5926)() TypeError: unable to simplify to complex approximation
The problem appears to be an automatic coercion to RDF or CDF. Maybe symbolic matrices should override the method.
Attachments (1)
Change History (11)
Changed 6 years ago by
comment:1 Changed 6 years ago by
comment:2 Changed 6 years ago by
- Status changed from new to needs_review
comment:3 Changed 6 years ago by
- Cc mmasdeu added
comment:4 Changed 6 years ago by
This ticket (and the added tests in particular) does not make much sense, unless there exists a symbolic max function. In my opinion, it would be better to return a NotImplementedError? than to return nonsense results.
comment:5 Changed 6 years ago by
Use max_symbolic then:
sage: max_symbolic(a,b) max(a, b)
comment:6 Changed 6 years ago by
- Keywords matrix symbolic added
- Status changed from needs_review to needs_work
- Work issues set to incorrect tests
comment:7 Changed 5 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:8 Changed 4 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:9 Changed 4 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:10 Changed 4 years ago by
- Milestone changed from sage-6.3 to sage-6.4
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Patch submitted. I also added an example to be sure, and corrected a little mistake in a test in sage/misc/functional.py