From: SourceForge.net <noreply@so...>  20031009 03:21:11

Bugs item #721575, was opened at 20030414 23:45 Message generated for change (Comment added) made by macrakis You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=721575&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: 2/sqrt(2) doesn't simplify Initial Comment: 2/sqrt(2) doesn't simplify. Similarly for 2/2^(2/3). On the other hand, x/sqrt(x) => sqrt(x). And of course sqrt(2) simplifies to itself  it doesn't become 2/sqrt(2)!! I believe the original examples should simplify to sqrt(2) and 2^(1/3). Note that 2^(4/3) => 2*2^(1/3) (the current behavior) is probably CORRECT, in order to make things like 10^(10/3) intelligible. Or is there something I'm missing? Maxima 5.9.0 gcl 2.5.0 mingw32 Windows 2000 Athlon  >Comment By: Stavros Macrakis (macrakis) Date: 20031008 23:21 Message: Logged In: YES user_id=588346 More examples. Righthand side is after ratsimp/algebraic. I believe the general simplifier should be giving those forms. 1/(2*2^(2/3)) 2^(1/3)/4 1/2^(2/3) 2^(1/3)/2 1/(2*SQRT(2)) SQRT(2)/4 1/SQRT(2) SQRT(2)/2 1/(2*2^(1/3)) 2^(2/3)/4 1/2^(1/3) 2^(2/3)/2 Things get worse with nonnumeric contents. In the following, each group of expressions denotes the same thing, but none simplifies to the others. I have put *** next to those forms which are the results of ratsimp/algebraic. Note that in several cases, there is more than one equivalent ratsimp'ed form.... 1/(a*b)^(5/2) 1/(a^2*b^2*SQRT(a*b)) *** SQRT(a*b)/(a^3*b^3) *** 1/(a*b)^(3/2) 1/(a*b*SQRT(a*b)) *** SQRT(a*b)/(a^2*b^2) *** 1/(a*b)^(7/6) 1/(a^(2/3)*b^(2/3)*SQRT(a*b)) *** SQRT(a*b)/(a^(5/3)*b^(5/3)) *** (a*b)^(5/6)/(a^2*b^2) *** 1/(a*b)^(5/6) *** 1/(a^(1/3)*b^(1/3)*SQRT(a*b)) *** (a*b)^(1/6)/(a*b) *** SQRT(a*b)/(a^(4/3)*b^(4/3)) *** 1/SQRT(a*b) *** SQRT(a*b)/(a*b) *** a^(1/3)*b^(1/3)/SQRT(a*b) *** 1/(a*b)^(1/6) *** SQRT(a*b)/(a^(2/3)*b^(2/3)) *** (a*b)^(5/6)/(a*b) *** Now it is true that these expressions are in fact not all equivalent as to principal value, but I will leave that exercise for later. Many of them are, and they are not being canonicalized.  Comment By: Stavros Macrakis (macrakis) Date: 20030417 14:53 Message: Logged In: YES user_id=588346 Yes, of course there are ways within Maxima to perform this simplification. But it should be the default in the general simplifer. The logic already appears to be in the general simplifier, but there is a bug in this particular case. If the general simplifier's philosophy were to leave such things untouched, why does it simplify x/sqrt(x) and the like?  Comment By: Barton Willis (willisb) Date: 20030417 14:44 Message: Logged In: YES user_id=570592 Try ratsimp with algebraic : true (C1) z : 2/sqrt(2); (D1) 2/SQRT(2) (C2) ratsimp(z); (D2) 2/SQRT(2) (C3) ratsimp(z),algebraic; (D3) SQRT(2) (C4) z : 2/2^(2/3); (D4) 2/2^(2/3) (C5) ratsimp(z); (D5) 2/2^(2/3) (C6) ratsimp(z),algebraic; (D6) 2^(1/3) (C7)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=721575&group_id=4933 