Opened 7 years ago
Closed 7 years ago
#5546 closed defect (fixed)
jacobian fails for pynac expressions
Reported by: | burcin | Owned by: | burcin |
---|---|---|---|
Priority: | major | Milestone: | sage-4.0 |
Component: | symbolics | Keywords: | |
Cc: | wstein, mhansen, robertwb | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | Work issues: | ||
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Reported by Alex Raichev on sage-support:
---------------------------------------------------------------------- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: var('x,y', ns=1) (x, y) sage: f= x+y sage: type(f) <type 'sage.symbolic.expression.Expression'> sage: jacobian(f,[x,y]) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /Users/arai021/<ipython console> in <module>() /Applications/sage/local/lib/python2.5/site-packages/sage/calculus/ functions.pyc in jacobian(functions, variables) 136 137 if not isinstance(variables, (tuple, list)) and not is_Vector(variables): 138 variables = [variables] 139 --> 140 return matrix([[diff(f, v) for v in variables] for f in functions]) /Applications/sage/local/lib/python2.5/site-packages/sage/calculus/ functional.pyc in derivative(f, *args, **kwds) 145 pass 146 if not isinstance(f, SymbolicExpression): --> 147 f = SR(f) 148 return f.derivative(*args, **kwds) 149 /Applications/sage/local/lib/python2.5/site-packages/sage/calculus/ calculus.pyc in __call__(self, x) 504 msg, s, pos = err.args 505 raise TypeError, "%s: %s !!! %s" % (msg, s [:pos], s[pos:]) --> 506 return self._coerce_impl(x) 507 508 def _coerce_impl(self, x): /Applications/sage/local/lib/python2.5/site-packages/sage/calculus/ calculus.pyc in _coerce_impl(self, x) 566 return self(x._sage_()) 567 else: --> 568 raise TypeError, "cannot coerce type '%s' into a SymbolicExpression."%type(x) 569 570 def _repr_(self): TypeError: cannot coerce type '<type 'sage.symbolic.expression.Expression'>' into a SymbolicExpression.
sage.symbolic.expression.Expression doesn't support .derivative(), and the interface to .diff() doesn't match the Sage conventions.
Attachments (4)
Change History (11)
comment:1 Changed 7 years ago by burcin
- Cc wstein mhansen added
- Status changed from new to assigned
- Summary changed from jacobian fails for pynac expressions to [with patch, needs review] jacobian fails for pynac expressions
comment:2 Changed 7 years ago by ncalexan
- Cc robertwb added
- Summary changed from [with patch, needs review] jacobian fails for pynac expressions to [with patch, needs work] jacobian fails for pynac expressions
With these two patches applied, you can get some wild things:
sage: var('x,y,z',ns=1) (x, y, z) sage: M = matrix(2,2,[x,y,z,x]) sage: M.base_ring() New Symbolic Ring sage: v = vector([x,y]) sage: v.base_ring() New Symbolic Ring sage: M * v Exception exceptions.TypeError: 'mutable matrices are unhashable' in 'sage.modules.free_module_element.FreeModuleElement._cmp_same_ambient_c' ignored <ERROR: mutable matrices are unhashable> (([x y] [z x])*x, ([x y] [z x])*y) sage: v * M (x^2 + y*z, 2*x*y) sage: M * v <ERROR: mutable matrices are unhashable> (([x y] [z x])*x, ([x y] [z x])*y) sage: v * M * v 2*x*y^2 + (x^2 + y*z)*x sage: v * (M * v) /Users/ncalexan/.sage/temp/dhcp_v007_000.mobile.uci.edu/36399/_Users_ncalexan__sage_init_sage_0.py:1: RuntimeWarning: tp_compare didn't return -1 or -2 for exception # -*- coding: utf-8 -*- ([x y] + ([x y]
comment:3 Changed 7 years ago by burcin
attachment:pynac-hash_exception.patch fixes exception handling during hashing in pynac and the problems reported by Nick in comment:2.
I will hold off on doing another pynac release to address this, since I don't know if mhansen made any changes which might be affected.
BTW, another pynac release, 0.1.6 in this case, would introduce circular dependencies in trac. :)
Comments on how to proceed?
comment:4 Changed 7 years ago by was
Comments on how to proceed?
I'd just like to remark that Mike Hansen is probably the best person I've ever met at using rebasing patches and using revision control systems. With him, I would not be worried about doing something that conflicts with what he has done or with circular trac dependencies.
comment:5 Changed 7 years ago by burcin
- Summary changed from [with patch, needs work] jacobian fails for pynac expressions to [with patch, needs review] jacobian fails for pynac expressions
The necessary changes for pynac, i.e., attachment:pynac-hash_exception.patch, is included in the new package for pynac-0.1.6 at #5777. The doctests in attachment:5546_doctests.patch are also posted in #5777.
This now introduces a circular dependency in trac. I hope this won't cause problems, since all these patches will go in together. Faster reviews in the future may prevent this from happening again.
Note that only:
needs to be applied from this ticket.
comment:6 Changed 7 years ago by burcin
- Milestone changed from sage-4.0.1 to sage-4.0
Some variants of these patches seem to be in 4.0.rc0. This bug should be closed. Trac doesn't allow me to close bugs any more though.
comment:7 Changed 7 years ago by mhansen
- Resolution set to fixed
- Status changed from assigned to closed
- Summary changed from [with patch, needs review] jacobian fails for pynac expressions to jacobian fails for pynac expressions
Attached patches allow forming matrices and vectors with pynac expressions, and make them use the multi_derivative framework. This makes the jacobian command in the example above work.