Issue 1435 in sympy: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero

Updates: Labels: EasyToFix Comment #2 on issue 1435 by ondrej.certik: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero http://code.google.com/p/sympy/issues/detail?id=1435 All tests pass except two printing ones: __ sympy/printing/pretty/tests/test_pretty.py:test_p

Issue 1435 in sympy: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero

Updates: Status: Started Comment #1 on issue 1435 by ondrej.certik: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero http://code.google.com/p/sympy/issues/detail?id=1435 Here is a patch fixing it: $ git diff diff --git a/sympy/core/function.py b/sympy/core/function.py

Issue 1435 in sympy: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero

Status: Accepted Owner: Labels: Type-Defect Priority-Medium New issue 1435 by ondrej.certik: f(x, y).diff(x, y) - f(x, y).diff(y, x) should simplify to zero http://code.google.com/p/sympy/issues/detail?id=1435 In [1]: f(x, y).diff(x, y) - f(x, y).diff(x, y) Out[1]: 0 In [2]: f(x, y).diff(

Issue 1427 in sympy: subs for sqrt(a/b) is wrong

Updates: Status: Started Comment #2 on issue 1427 by ondrej.certik: subs for sqrt(a/b) is wrong http://code.google.com/p/sympy/issues/detail?id=1427 The attached patch fixes it. In [1]: var("a b") Out[1]: (a, b) In [2]: e = sqrt(a/b) In [3]: e Out[3]: ⎽⎽⎽ ╱ a ╱ ─ ╲╱ b I

Issue 1434 in sympy: substitution doesn't work for sqrt()

Updates: Cc: fab...@fseoane.net Comment #4 on issue 1434 by ondrej.certik: substitution doesn't work for sqrt() http://code.google.com/p/sympy/issues/detail?id=1434 Btw, the following patch broke it: http://git.sympy.org/?p=sympy.git;a=commitdiff;h=b1127626eafb95e6bb7032bd9d444e6bfa42

Issue 1309 in sympy: implement backward chaining for rules

Updates: Labels: -Priority-Critical Priority-High Comment #12 on issue 1309 by ondrej.certik: implement backward chaining for rules http://code.google.com/p/sympy/issues/detail?id=1309 I think this is not critical, just high. -- You received this message because you are listed in the

Issue 1263 in sympy: Invalid movement of roots across fractions

Comment #13 on issue 1263 by ondrej.certik: Invalid movement of roots across fractions http://code.google.com/p/sympy/issues/detail?id=1263 Oops, this is in already. Sorry for the noise. -- You received this message because you are listed in the owner or CC fields of this issue, or because yo

Issue 1263 in sympy: Invalid movement of roots across fractions

Updates: Labels: -Priority-Medium -Milestone-Release0.6.4 Priority-High Milestone-Release0.6.5 Comment #12 on issue 1263 by ondrej.certik: Invalid movement of roots across fractions http://code.google.com/p/sympy/issues/detail?id=1263 I'll look into it before a release. -- You recei

Issue 1434 in sympy: substitution doesn't work for sqrt()

Comment #3 on issue 1434 by ondrej.certik: substitution doesn't work for sqrt() http://code.google.com/p/sympy/issues/detail?id=1434 When writing the tests, please test all the code here: if base.is_positive: return result elif exp.q =

Issue 1434 in sympy: substitution doesn't work for sqrt()

Updates: Labels: -Priority-High Priority-Critical Comment #2 on issue 1434 by ondrej.certik: substitution doesn't work for sqrt() http://code.google.com/p/sympy/issues/detail?id=1434 Here is the fix for the issue, all tests pass (except that limit above): diff --git a/sympy/core/numbe

Issue 1434 in sympy: substitution doesn't work for sqrt()

Updates: Status: Started Comment #1 on issue 1434 by ondrej.certik: substitution doesn't work for sqrt() http://code.google.com/p/sympy/issues/detail?id=1434 Here is a fix for the sqrt(x*y) problem: diff --git a/sympy/core/mul.py b/sympy/core/mul.py index 795b293..f63f805 100644 --- a/

Issue 1434 in sympy: substitution doesn't work for sqrt()

Status: Accepted Owner: Labels: Type-Defect Priority-High Milestone-Release0.6.5 WrongResult New issue 1434 by ondrej.certik: substitution doesn't work for sqrt() http://code.google.com/p/sympy/issues/detail?id=1434 In [6]: sqrt(1-x**2) Out[6]: ╱ 2 ╲╱ 1 - x In [7]: sqr

Issue 1433 in sympy: Integrate returns different result than from Matlab

Updates: Labels: WrongResult Comment #1 on issue 1433 by hazelnusse: Integrate returns different result than from Matlab http://code.google.com/p/sympy/issues/detail?id=1433 (No comment was entered for this change.) -- You received this message because you are listed in the owner or C

Issue 1433 in sympy: Integrate returns different result than from Matlab

Status: Accepted Owner: hazelnusse Labels: Type-Defect Priority-Medium New issue 1433 by hazelnusse: Integrate returns different result than from Matlab http://code.google.com/p/sympy/issues/detail?id=1433 [matlab] >> integrand = 2*X*X + 2*Y*Y - 1 integrand = 2*X^2+2*Y^2-1 >> res = int(integra

Issue 1431 in sympy: ratsimp improvement

Comment #1 on issue 1431 by smichr: ratsimp improvement http://code.google.com/p/sympy/issues/detail?id=1431 I reported in issue 1432 that there were problems when applying simplify to the above expression. I also added a comment there that I had a definition of k in place that defined k in

Issue 1432 in sympy: simplify gets hung up on this expression

Comment #1 on issue 1432 by smichr: simplify gets hung up on this expression http://code.google.com/p/sympy/issues/detail?id=1432 When you try this you likely won't have a problem, just like I don't now while trying to reproduce this. But after sending this in, I noticed that the variable k

Issue 1432 in sympy: simplify gets hung up on this expression

Status: New Owner: Labels: Type-Defect Priority-Medium New issue 1432 by smichr: simplify gets hung up on this expression http://code.google.com/p/sympy/issues/detail?id=1432 Simplify seems to get hung up when trying to simplify this expression: -x1 + F1/(Gc + k) + Gc*x1/(Gc + k) + Gc*xd/(

Issue 1431 in sympy: ratsimp improvement

Status: New Owner: Labels: Type-Defect Priority-Medium New issue 1431 by smichr: ratsimp improvement http://code.google.com/p/sympy/issues/detail?id=1431 A recent post about simplifications made me wonder if something might be done to make ratsimp a little better at simlification. Here's an