Hi, Pursuant to
http://groups.google.com/group/sage-support/browse_thread/thread/f05932c2048f0ac0/ I am now trying to solve a system of equations using sympy instead of Maxima to see if sympy's behavior is closer to that of Mathematica. The following example is from the sympy tutorial (where it works fine in regular sympy) but is not included in the the Sage documentation on how to use the sympy interface. Can someone explain what is wrong? sage: var('x y') sage: from sympy import solve, Symbol sage: x = Symbol("x") sage: y = Symbol("y") sage: solve(x**4 == 1, x) # fine [I, 1, -1, -I] sage: solve([x + 5*y == 2, -3*x + 6*y == 15], [x, y]) # error --------------------------------------------------------------------------- <type 'exceptions.ValueError'> Traceback (most recent call last) /media/sda4/sage-2.10.2/<ipython console> in <module>() /media/sda4/sage-2.10.2/local/lib/python2.5/site-packages/sympy/ solvers/solvers.py in solve(eq, syms, simplified) 98 equ = eq[i].lhs - eq[i].rhs 99 else: --> 100 equ = Basic.sympify(eq[i]) 101 102 content = collect(equ.expand(), syms, evaluate=False) /media/sda4/sage-2.10.2/local/lib/python2.5/site-packages/sympy/core/ basic.py in sympify(a, sympify_lists) 267 pass 268 if a.strip() != a: --> 269 return Basic.sympify(a.strip()) 270 raise ValueError("%r is NOT a valid SymPy expression" % a) 271 /media/sda4/sage-2.10.2/local/lib/python2.5/site-packages/sympy/core/ basic.py in sympify(a, sympify_lists) 268 if a.strip() != a: 269 return Basic.sympify(a.strip()) --> 270 raise ValueError("%r is NOT a valid SymPy expression" % a) 271 272 @Memoizer('Basic', MemoizerArg((type, type(None), tuple), name='type'), return_value_converter = lambda obj: obj.copy()) <type 'exceptions.ValueError'>: '6 y - 3 x == 15' is NOT a valid SymPy expression sage: For some reason, it gets transformed into '6 y - 3 x == 15' instead of '6*y - 3*x == 15' . Thanks, Ben --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
