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From: SourceForge.net <noreply@so...>  20061109 04:13:04

Bugs item #626721, was opened at 20021022 03:15 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=626721&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Trigonometry Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: logarc of atan2 wrong Initial Comment: res : logarc(atan2(y,x))$ rectform(res),y=1,x=1; => %pi/4 BUT atan2(1,1) => 3*%pi/4 The fix is to change the formula in $logarc and in simpatan2. Currently, logarc(atan2(y,x)) => logarc(atan (y/x)), which gives incorrect results as above. This formula should be replaced by %i*log((y+%i*x)/sqrt(x^2+y^2))  >Comment By: Raymond Toy (rtoy) Date: 20061108 23:13 Message: Logged In: YES user_id=28849 Isn't this formula also wrong? For y=1, x=1, the formula becomes %i*log((1%i)/sqrt(2)). But log is the principal log so we still get %pi/4. I think it would be better to make atan2 be in the range (%pi,%pi].  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=626721&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 03:14:26

Bugs item #593344, was opened at 20020809 22:14 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=593344&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: limit(abs(infinity)) strange result (was: infinite loop) Initial Comment: limit(abs(infinity)) appears to get into an infinite loop.  >Comment By: Raymond Toy (rtoy) Date: 20061108 22:14 Message: Logged In: YES user_id=28849 Current CVS returns infinity. That seems right. Closing this bug.  Comment By: Robert Dodier (robert_dodier) Date: 20050802 01:48 Message: Logged In: YES user_id=501686 Well, I don't see an infinite loop, but I do see this: (%i3) limit(abs(infinity)); (%o3) 'limit(abs(?foo),?foo,infinity) Maybe this is actually OK ?? Not sure. Maxima version: 5.9.1.1cvs Maxima build date: 10:5 7/28/2005 host type: i686redhatlinuxgnu lispimplementationtype: CLISP lispimplementationversion: 2.33.2 (20040602)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=593344&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 03:13:10

Bugs item #535363, was opened at 20020326 14:21 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=535363&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Daniel Lemire (lemire) Assigned to: Nobody/Anonymous (nobody) Summary: Hospital gives up without warning Initial Comment: Behavior: (C1) limit(exp(1/x)/x^5,x,0,PLUS); (D1) 0 (C2) limit(exp(1/x)/x^6,x,0,PLUS);  1/x %E (D2) limit  x > 0+ 6 x Explanation (Richard Fateman): lhospitallim is set to 5. Yes it is arbitrary, but you can change it. Expected behavior: Wouldn't it be nicer if there was some warning message telling us "I stopped, but by changing this variable you could maybe get me to evaluate the limit in full"...? This gives the wrong impression... like "oh! Maxima can't solve that!". Further comments (Richard Fateman): I suppose this could be done, but it might also be the case that after giving up on L'Hopital's rule it tries something else that might succeed. The source code for limit is available. Further comments (James Amundson): I agree. It also might be a good idea to increase the default value. Computers are bigger and stronger now.  >Comment By: Raymond Toy (rtoy) Date: 20061108 22:13 Message: Logged In: YES user_id=28849 I think we should just increase the default to 8 (just as arbitrary as 5) and close this bug. Alternatively, we could make L'Hopital check to see if the numerator or denominator is a polynomial and change the limit appropriately.  Comment By: Robert Dodier (robert_dodier) Date: 20060326 18:21 Message: Logged In: YES user_id=501686 For the record, same behavior in Maxima 5.9.3.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=535363&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 03:05:21

Bugs item #593357, was opened at 20020809 23:36 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=593357&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: Various problems with Limit and Atan2 Initial Comment: limit(atan2(sin(x),1/x),x,0) returns  FALSE Note that this only happens when the argument expression is negated (!).  limit(atan2(x,2*x),x,0) and limit(atan2(2*x^2,x^2),x,0) give the error Atan2(0,0) has been generated. But the first should give IND, and the second should give atan(2).  limit(atan2(x*abs(a),x),inf) correctly gives atan(abs(a)), but limit(atan2(x,abs(a)*x),x,inf) gives the noun form   >Comment By: Raymond Toy (rtoy) Date: 20061108 22:05 Message: Logged In: YES user_id=28849 Current CVS (including the fix for bug 626697 does this: limit(atan2(sin(x),1/x),x,0) > nounform limit(atan2(x*abs(a),x),inf) > atan(a) limit(atan2(x,abs(a)*x),x,inf) > atan(1/a) limit(atan2(x,2*x),x,0) and limit(atan2(2*x^2,x^2),x,0) both return atan2(0,0) generated.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=593357&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 02:59:59

Bugs item #626697, was opened at 20021022 01:27 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=626697&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: limit(atan2(y,x),y,minf) => FALSE Initial Comment: limit(atan2(y,x),y,minf) => FALSE The fix is in the very last clause of SIMPLIMIT. Currently, it is (if $limsubst <stuff>) It should be (if $limsubst <stuff> (nounlimit exp var val))  >Comment By: Raymond Toy (rtoy) Date: 20061108 21:59 Message: Logged In: YES user_id=28849 Fixed as suggested. Closing.  Comment By: Stavros Macrakis (macrakis) Date: 20031009 15:38 Message: Logged In: YES user_id=588346 Same problem, same solution for limit(BETA((a+1)/b,(ba 1)/b)/b,a,b1);  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=626697&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 02:49:50

Bugs item #635606, was opened at 20021108 12:47 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=635606&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: limit(abs(log(x))) internal error, UND Initial Comment: Maxima 5.5/Windows/gcl limit(abs(log(x)),x,0) Error: The tag LIMIT is undefined. Should of course be INF. More controversially, perhaps, limit(log(x),x,0) gives UND  I believe it should give INFINITY; after all, limit(log (x),x,0,minus) gives INFINITY.  >Comment By: Raymond Toy (rtoy) Date: 20061108 21:49 Message: Logged In: YES user_id=28849 The error no longer occurs in current CVS. It returns UND, after asking if x is positive or negative. Why should the answer be INF? log(x) is undefined for negative real x.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=635606&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 02:19:05

Bugs item #1036901, was opened at 20040929 05:53 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1036901&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Jaroslaw Piskorski (jaropis) Assigned to: Nobody/Anonymous (nobody) Summary: tlimit(7^(n^2)/8^n,n,inf); wrong result Initial Comment: Maxima returns minf, while it should return inf here.  >Comment By: Raymond Toy (rtoy) Date: 20061108 21:19 Message: Logged In: YES user_id=28849 I think the bug is in taylor, which is called by taylim, via limit. taylor(7^(n^2)/8^n,n,inf,1) > log(8)*n+1 I don't think that that is right.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1036901&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 01:59:10

Bugs item #1100129, was opened at 20050111 08:05 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1100129&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: limit finds not a limit from defint, but finds it from topl Initial Comment: I found a problem Maxima hangs at, could someone take a look? I tried to solve a definite integration problem, and then I tried to track down the problem in maxima internals. I found that $limit fails on an expression which is easily solved from toplevel. Any ideas on what's happening? One more question: unless I explicilty do (trace sratsimp behaviorbydiff), :bt reporst a stop in $limit. It take quite a time to type in most of limit.lisp function names to get to the actual timeeater. Please, show me a technique to dig an actual call sequence?  Andrei Zorine Maxima 5.9.1 http://maxima.sourceforge.net Using Lisp Kyoto Common Lisp GCL 2.6.5 (aka GCL) Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. This is a development version of Maxima. The function bug_report() provides bug reporting information. (%i1) (sqrt(sqrt(x^2+1)+x)sqrt(sqrt(x^2+1)x))/x/(x^2+1); 2 2 SQRT(SQRT(x + 1) + x)  SQRT(SQRT(x + 1)  x) (%o1)  2 x (x + 1) (%i2) limit(x*%,x,0); (%o2) 0 (%i3) defint(%o1,x,0,inf); Maxima encountered a Lisp error: Console interrupt. Automatically continuing. To reenable the Lisp debugger set *debuggerhook* to nil. (%i4) :lisp(trace sratsimp) (SRATSIMP) (%i4) :lisp(trace behaviorbydiff) (BEHAVIORBYDIFF) (%i5) :lisp(setq *debuggerhook* nil) NIL (%i5) defint(%o1,x,0,inf); console interrupt. Fast links are on: do (usefastlinks nil) for debugging Broken at SYSTEM::CLCSTERMINALINTERRUPT. Type :H for Help. 1 (Continue) Continues execution. 2 (Abort) Return to top level. dbl:MAXIMA>>:bt #0 CLCSTERMINALINTERRUPT {loc0=t} [ihs=17] #1 TRACECALL {tempname=nil,args=nil,cond=nil,entrycond=((system::arglist (#))),entry=nil,exi...} [ihs=16] #2 SRATSIMP {(#0=(mplus . #1=(simp)) (#2=(mtimes . #1#) (#3=# 1 2) (#4=# #5=# 1) ...) (#2#...} [ihs=15] #3 TRACECALL {tempname=nil,args=(#0=(mplus . #1=(simp)) (#2=(mtimes . #1#) (#3=# 1 2) (#4=#...} [ihs=14] #4 BEHAVIORBYDIFF {(#0=(mplus . #1=(simp)) (#2=(mtimes . #1#) 1 (#3=# # 1) ...) (#2# (#3# # 1) ...} [ihs=13] #5 $LIMIT {loc0=((mtimes . #0=(simp)) (#1=(mexpt . #0#) (#2=# 1 #) 1) (#2# (# 1 #) (#1# ...} [ihs=12] #6 LIMITNOERR {loc0=((mtimes . #0=(simp)) (#1=(mexpt . #0#) (#2=# 1 #) 1) (#2# (# 1 #) (#1# ...} [ihs=11] #7 MACSYMATOPLEVEL {inputstream=:internal,batchflag=$inf,loc2=nil,loc3=stringchar,loc4="0",loc...} [ihs=10] #8 RUN {} [ihs=6] #9 TOPLEVEL {loc0=nil,loc1=nil,loc2=nil,loc3=(lambdablock run nil ...)} [ihs=5] #10 FUNCALL {loc0=#<compiledfunction system:toplevel>,loc1=nil,loc2=0,loc3=0,loc4=nil,loc5...} [ihs=4] NIL  >Comment By: Raymond Toy (rtoy) Date: 20061108 20:59 Message: Logged In: YES user_id=28849 I'm not familiar with GCL's backtrace mechanism. CMUCL and SBCL produce much easier to understand backtraces. In any case, you can see there's a call to $limit. trace(limit) shows that it's getting stuck finding the limit of (sqrt(sqrt(1+eps^2)+eps)sqrt(sqrt(1+eps^2)eps))/(1+eps^2) for eps > 0 from above. Don't know why.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1100129&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 01:35:22

Bugs item #1106912, was opened at 20050121 14:07 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1106912&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) >Summary: limit(x/sin(x)^2,x,inf) Initial Comment: limit(x/sin(x)^2,x,inf) => UND actually = inf  >Comment By: Raymond Toy (rtoy) Date: 20061108 20:35 Message: Logged In: YES user_id=28849 Fix summary. Problem still exists in current CVS.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1106912&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 01:33:53

Bugs item #1281736, was opened at 20050904 15:26 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1281736&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Vadim V. Zhytnikov (vvzhy) Assigned to: Nobody/Anonymous (nobody) Summary: limit((x/log(x))*(x^(1/x)1),x,inf)  wrong result Initial Comment: (%i1) limit((x/log(x))*(x^(1/x)1),x,inf); (%o1) inf Correct result should be 1  >Comment By: Raymond Toy (rtoy) Date: 20061108 20:33 Message: Logged In: YES user_id=28849 Current CVS returns the nounform for the limit. Better than inf, but could be better. tlimit actually returns 1 in this case.  Comment By: Stavros Macrakis (macrakis) Date: 20050928 10:25 Message: Logged In: YES user_id=588346 This is a bug. Even worse, tlimit also doesn't work, and for no good reason: tlimit(...) => nounform but limit ( taylor ( (x/log(x))*(x^(1/x)1) , x, inf, 0 ) ) => 0  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1281736&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 01:27:37

Bugs item #1593083, was opened at 20061108 20:27 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1593083&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Raymond Toy (rtoy) Assigned to: Nobody/Anonymous (nobody) Summary: tlimit(t^2*exp(4*t/38*exp(t)),t,inf) gives error Initial Comment: tlimit(t^2*exp(4*t/38*exp(t)),t,inf) produces an error: Invalid call to varexpand  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1593083&group_id=4933 
From: SourceForge.net <noreply@so...>  20061109 01:17:24

Bugs item #1548643, was opened at 20060829 11:09 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1548643&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Limit Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: limit with abs: tag LIMIT is undefined Initial Comment: ex:abs(sqrt(11/x)1) limit(ex,x,0); Maxima encountered a Lisp error: Error in PROGN [or a callee]: The tag LIMIT is undefined.  >Comment By: Raymond Toy (rtoy) Date: 20061108 20:17 Message: Logged In: YES user_id=28849 Suggested fix implemented some time ago, so we don't get an error anymore. Closing.  Comment By: Raymond Toy (rtoy) Date: 20060830 21:40 Message: Logged In: YES user_id=28849 In mabssubst, near the very beginning, there's the line (equal ($imagpart (limit d var val 'think)) 0) Replace the call to limit with (let ((v (limitcatch d var val))) (unless v (throw 'mabs '$und)) v) This causes the given test to return "und". Not sure if that's what we want to return, but certainly better than an error. The testsuite passes with this change, FWIW.  Comment By: Raymond Toy (rtoy) Date: 20060830 19:49 Message: Logged In: YES user_id=28849 Ok. This is caused by mabssubst calling limit, but forgetting that limit might throw to the tag LIMIT. Not exactly sure what the right solution would be. Perhaps in that case mabssubst should, itself, throw 'mabs 'retn?  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1548643&group_id=4933 
From: SourceForge.net <noreply@so...>  20061108 22:31:58

Bugs item #1588623, was opened at 20061101 08:42 Message generated for change (Settings changed) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None Status: Open Resolution: None >Priority: 1 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: romberg with % or %o argument Initial Comment: (%i1) sqrt(1+x^3); (%o1) sqrt(x^3+1) (%i2) romberg(%, x,0,1); Maxima encountered a Lisp error: Also, the command romberg(%o1,x,0,1) gives a Lisp error. This works OK: (%i4) romberg(sqrt(1+x^3), x,0,1); (%o4) 1.111447999508385 (%i1) build_info(); Maxima version: 5.10.0 Maxima build date: 19:9 9/21/2006 host type: i686pcmingw32 lispimplementationtype: GNU Common Lisp (GCL) lispimplementationversion: GCL 2.6.7  Comment By: Barton Willis (willisbl) Date: 20061108 06:00 Message: Logged In: YES user_id=895922 I agree. It would be good to have a function for big float numerical integration. Not that romberg works with big floats: (%i2) romberg(sin(x^2),x,0,1); (%o2) 0.31026884083166872 (%i3) rombergtol : 1.0b12; (%o3) 1.0b12 (%i4) romberg(sin(x^2),x,0,1); Maxima encountered a Lisp error: Error in MACSYMATOPLEVEL [or a callee]: ((BIGFLOAT SIMP 56) ...  Comment By: Robert Dodier (robert_dodier) Date: 20061105 10:14 Message: Logged In: YES user_id=501686 I don't recommend trying to fix romberg. The quadpack functions are more extensive implementations of the same basic idea (extrapolation from simple quadrature ruls); quadpack subsumes romberg and goes much farther. I'd like to cut out romberg entirely.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 
From: SourceForge.net <noreply@so...>  20061108 12:00:15

Bugs item #1588623, was opened at 20061101 08:42 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: romberg with % or %o argument Initial Comment: (%i1) sqrt(1+x^3); (%o1) sqrt(x^3+1) (%i2) romberg(%, x,0,1); Maxima encountered a Lisp error: Also, the command romberg(%o1,x,0,1) gives a Lisp error. This works OK: (%i4) romberg(sqrt(1+x^3), x,0,1); (%o4) 1.111447999508385 (%i1) build_info(); Maxima version: 5.10.0 Maxima build date: 19:9 9/21/2006 host type: i686pcmingw32 lispimplementationtype: GNU Common Lisp (GCL) lispimplementationversion: GCL 2.6.7  >Comment By: Barton Willis (willisbl) Date: 20061108 06:00 Message: Logged In: YES user_id=895922 I agree. It would be good to have a function for big float numerical integration. Not that romberg works with big floats: (%i2) romberg(sin(x^2),x,0,1); (%o2) 0.31026884083166872 (%i3) rombergtol : 1.0b12; (%o3) 1.0b12 (%i4) romberg(sin(x^2),x,0,1); Maxima encountered a Lisp error: Error in MACSYMATOPLEVEL [or a callee]: ((BIGFLOAT SIMP 56) ...  Comment By: Robert Dodier (robert_dodier) Date: 20061105 10:14 Message: Logged In: YES user_id=501686 I don't recommend trying to fix romberg. The quadpack functions are more extensive implementations of the same basic idea (extrapolation from simple quadrature ruls); quadpack subsumes romberg and goes much farther. I'd like to cut out romberg entirely.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 
From: Ossian Westergard <barbero@hy...>  20061108 10:39:59

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From: SourceForge.net <noreply@so...>  20061107 16:34:08

Bugs item #1265894, was opened at 20050822 00:27 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1265894&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None >Status: Closed >Resolution: Duplicate Priority: 5 Private: No Submitted By: Robert Dodier (robert_dodier) Assigned to: Nobody/Anonymous (nobody) Summary: integrate (exp (a*x), x, 0, inf) => 0 after choosing zero Initial Comment: (%i1) integrate (exp (a*x), x, 0, inf); Is a positive, negative, or zero? z; Principal Value(%o1) 0  but  (%i2) a: 0; (%o2) 0 (%i3) integrate (exp (a*x), x, 0, inf); Integral is divergent Observed on 5.9.1cvs / gcl 2.6.6 but same behavior observed in 5.9.1 on cmucl 19a, and 5.9.1cvs / clisp 2.33.  >Comment By: Raymond Toy (rtoy) Date: 20061107 11:34 Message: Logged In: YES user_id=28849 This is duplicate of Bug 887646. Closing.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1265894&group_id=4933 
From: SourceForge.net <noreply@so...>  20061107 15:55:10

Bugs item #1073338, was opened at 20041125 13:21 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1073338&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Robert Dodier (robert_dodier) Assigned to: Nobody/Anonymous (nobody) Summary: integrate yields incorrect result on rational function Initial Comment: "integrate" yields incorrect results on some rational functions. "Division by 0" is strange. The definite integral below is certainly greater than 0 as the integrand is positive over [0, 1]. "integrate (1/((x3)^4+1/2), x)" returns the noun form, so maybe (maybe) what happens is that the noun form is evaluated at the limits of integration and it's the same, hence 0 is the result. (Just guessing there.) Note that the difference between the two integrands is that one is 1/(something + 1), while the other is 1/(same something + 1/2).  (%i1) integrate (1/((x3)^4+1), x, 0, 1); Division by 0  an error. Quitting. To debug this try DEBUGMODE(TRUE); (%i2) integrate (1/((x3)^4+1/2), x, 0, 1); (%o2) 0 (%i3) build_info (); Maxima version: 5.9.1 Maxima build date: 21:24 9/23/2004 host type: i686pclinuxgnu lispimplementationtype: CMU Common Lisp lispimplementationversion: 19a  Same behavior observed in CVS build of 2004/11/24.  >Comment By: Raymond Toy (rtoy) Date: 20061107 10:55 Message: Logged In: YES user_id=28849 Fixed as suggested. This is really a workaround instead of the true fix.  Comment By: Raymond Toy (rtoy) Date: 20061106 13:13 Message: Logged In: YES user_id=28849 Recent changes in defint.lisp and residue.lisp has fixed the issue with the integrate(1/((x3)^4+1),x,0,1). For integrate(1/((x3)^4+1/2),x,0,1), it does seem to be either a gcd or residue problem. We can work around this issue by making 2 changes in residu.lisp. In the function RES, for the case of simple poles, we can use RES1 instead of $RESIDUE. In the function RES1, we need to call $RECTFORM for each pole to make is simpler. With these changes applied, this integral can be evaluated. However, the answer takes some time and is quite messy. We can get the simpler result by using factor(expand(sqrtdenest(<foo>))). The answer is: (2*atan((sqrt(2)4*2^(1/4)+8)/(49*2^(3/4)+sqrt(2)8)) log((2^(3/4)+12*sqrt(2)+73*2^(1/4)2)/(33*2^(1/4))) +log((2^(3/4)12*sqrt(2)+73*2^(1/4)+2)/(33*2^(1/4))) 2*atan((sqrt(2)+4*2^(1/4)+8)/(49*2^(3/4)+sqrt(2)8))) /(2*2^(3/4)) Numerical evaluation of this compares favorably with the numerical result from quad_qags.  Comment By: Stavros Macrakis (macrakis) Date: 20050130 18:04 Message: Logged In: YES user_id=588346 This is apparently another GCD problem. Fixed by setting the 'algebraic' flag: integrate (1/((x3)^4+1), x, 0, 1),algebraic:true For the indefinite integral, you can factor over the Gaussians then use partfrac: integrate ( partfrac ( gfactor( 1/((x3)^4+1) ), x ), x ) You can simplify the result using ratsimp(rectform(...)) s  Comment By: Nobody/Anonymous (nobody) Date: 20050118 16:17 Message: Logged In: NO Two remarks: The method that Maxima uses to solve such integrals is integration by residues. Trace (residue) shows that this function is called with the correct arguments but answers zeroes for integrate (1/((x3)^4+1/2), x, 0, 1); and runs into a division by zero for the other integral. The indefinite integrals can be solved with changevar: 'Integrate(1/((x3)^4+1/2), x); changevar (%, x  3  y ,y ,x); ev (%, Integrate);  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1073338&group_id=4933 
From: SourceForge.net <noreply@so...>  20061106 18:14:03

Bugs item #1073338, was opened at 20041125 13:21 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1073338&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Robert Dodier (robert_dodier) Assigned to: Nobody/Anonymous (nobody) Summary: integrate yields incorrect result on rational function Initial Comment: "integrate" yields incorrect results on some rational functions. "Division by 0" is strange. The definite integral below is certainly greater than 0 as the integrand is positive over [0, 1]. "integrate (1/((x3)^4+1/2), x)" returns the noun form, so maybe (maybe) what happens is that the noun form is evaluated at the limits of integration and it's the same, hence 0 is the result. (Just guessing there.) Note that the difference between the two integrands is that one is 1/(something + 1), while the other is 1/(same something + 1/2).  (%i1) integrate (1/((x3)^4+1), x, 0, 1); Division by 0  an error. Quitting. To debug this try DEBUGMODE(TRUE); (%i2) integrate (1/((x3)^4+1/2), x, 0, 1); (%o2) 0 (%i3) build_info (); Maxima version: 5.9.1 Maxima build date: 21:24 9/23/2004 host type: i686pclinuxgnu lispimplementationtype: CMU Common Lisp lispimplementationversion: 19a  Same behavior observed in CVS build of 2004/11/24.  >Comment By: Raymond Toy (rtoy) Date: 20061106 13:13 Message: Logged In: YES user_id=28849 Recent changes in defint.lisp and residue.lisp has fixed the issue with the integrate(1/((x3)^4+1),x,0,1). For integrate(1/((x3)^4+1/2),x,0,1), it does seem to be either a gcd or residue problem. We can work around this issue by making 2 changes in residu.lisp. In the function RES, for the case of simple poles, we can use RES1 instead of $RESIDUE. In the function RES1, we need to call $RECTFORM for each pole to make is simpler. With these changes applied, this integral can be evaluated. However, the answer takes some time and is quite messy. We can get the simpler result by using factor(expand(sqrtdenest(<foo>))). The answer is: (2*atan((sqrt(2)4*2^(1/4)+8)/(49*2^(3/4)+sqrt(2)8)) log((2^(3/4)+12*sqrt(2)+73*2^(1/4)2)/(33*2^(1/4))) +log((2^(3/4)12*sqrt(2)+73*2^(1/4)+2)/(33*2^(1/4))) 2*atan((sqrt(2)+4*2^(1/4)+8)/(49*2^(3/4)+sqrt(2)8))) /(2*2^(3/4)) Numerical evaluation of this compares favorably with the numerical result from quad_qags.  Comment By: Stavros Macrakis (macrakis) Date: 20050130 18:04 Message: Logged In: YES user_id=588346 This is apparently another GCD problem. Fixed by setting the 'algebraic' flag: integrate (1/((x3)^4+1), x, 0, 1),algebraic:true For the indefinite integral, you can factor over the Gaussians then use partfrac: integrate ( partfrac ( gfactor( 1/((x3)^4+1) ), x ), x ) You can simplify the result using ratsimp(rectform(...)) s  Comment By: Nobody/Anonymous (nobody) Date: 20050118 16:17 Message: Logged In: NO Two remarks: The method that Maxima uses to solve such integrals is integration by residues. Trace (residue) shows that this function is called with the correct arguments but answers zeroes for integrate (1/((x3)^4+1/2), x, 0, 1); and runs into a division by zero for the other integral. The indefinite integrals can be solved with changevar: 'Integrate(1/((x3)^4+1/2), x); changevar (%, x  3  y ,y ,x); ev (%, Integrate);  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1073338&group_id=4933 
From: SourceForge.net <noreply@so...>  20061106 16:28:49

Bugs item #733071, was opened at 20030506 00:19 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=733071&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: Defint unsimplified result Initial Comment: integrate(exp(x^2%i*2*%pi*x*s),x,minf,inf) => SQRT(%PI)*%E^(%I^2*%PI^2*s^2) Note the unsimplified %i^2.  >Comment By: Raymond Toy (rtoy) Date: 20061106 11:28 Message: Logged In: YES user_id=28849 FWIW, this is caused by the call to $ratsimp in linpower in defint.lisp. Something about it prevents simplifying %i^2 to 1.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=733071&group_id=4933 
From: SourceForge.net <noreply@so...>  20061106 14:37:28

Bugs item #1590528, was opened at 20061104 11:27 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1590528&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core Group: None Status: Open Resolution: None Priority: 1 Private: No Submitted By: Raymond Toy (rtoy) Assigned to: Nobody/Anonymous (nobody) Summary: Does debugmode(true) actually do anything? Initial Comment: debugmode(true)$ integrate((4*x^2+8*x+4)/(17*x^4+64*x^3+96*x^2+64*x+16),x,0,inf); This should give a division by zero error, and we enter debug mode: (dbm:1) :bt (dbm:1) I tried this with gcl, clisp, and cmucl. Nothing really seems to happen. Does debugmode work for anything? At least with CMUCL, it doesn't seem to matter too much, because I can press Cc to get to CMUCL's debugger which can then produce backtraces and such.  >Comment By: Raymond Toy (rtoy) Date: 20061106 09:37 Message: Logged In: YES user_id=28849 After reading your comments and the examples in the user manual, I see that debugmode is useful. I also agree that we should change the "Quitting" part. However, I propose to leave the debugmode(true) part in. Even though it can't debug Lisp functions and such, it's quite useful because execution stops at the error and I can press Cc (in CMUCL) and use CMUCL's debugger to figure out where the problem is. I suppose I could use (setf *breakonsignals* t), but this is still useful.  Comment By: Robert Dodier (robert_dodier) Date: 20061105 11:11 Message: Logged In: YES user_id=501686 Maxima debugmode can print a backtrace of functions defined in Maxima by := . So far as I can tell, debugmode doesn't know anything about functions defined by defun or defmfun or defmspec. Given that most functions in Maxima are defined by defun, defmfun, and defmspec, it is not very informative to use debugmode. Since debugmode is useful in a certain context (namely debugging userdefined functions) I think we should keep it, but let's change "  an error. Quitting. To debug this try debugmode(true);" to just "  an error." (i.e. cut out the recommendation to use debugmode, which is usually not helpful, and also the "Quitting." because, in fact, Maxima is not executing (quit) nor quit()).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1590528&group_id=4933 
From: SourceForge.net <noreply@so...>  20061105 16:14:51

Bugs item #1588623, was opened at 20061101 07:42 Message generated for change (Comment added) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. >Category: Lisp Core  Integration Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: romberg with % or %o argument Initial Comment: (%i1) sqrt(1+x^3); (%o1) sqrt(x^3+1) (%i2) romberg(%, x,0,1); Maxima encountered a Lisp error: Also, the command romberg(%o1,x,0,1) gives a Lisp error. This works OK: (%i4) romberg(sqrt(1+x^3), x,0,1); (%o4) 1.111447999508385 (%i1) build_info(); Maxima version: 5.10.0 Maxima build date: 19:9 9/21/2006 host type: i686pcmingw32 lispimplementationtype: GNU Common Lisp (GCL) lispimplementationversion: GCL 2.6.7  >Comment By: Robert Dodier (robert_dodier) Date: 20061105 09:14 Message: Logged In: YES user_id=501686 I don't recommend trying to fix romberg. The quadpack functions are more extensive implementations of the same basic idea (extrapolation from simple quadrature ruls); quadpack subsumes romberg and goes much farther. I'd like to cut out romberg entirely.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1588623&group_id=4933 
From: SourceForge.net <noreply@so...>  20061105 16:11:10

Bugs item #1590528, was opened at 20061104 09:27 Message generated for change (Comment added) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1590528&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core Group: None Status: Open Resolution: None Priority: 1 Private: No Submitted By: Raymond Toy (rtoy) Assigned to: Nobody/Anonymous (nobody) Summary: Does debugmode(true) actually do anything? Initial Comment: debugmode(true)$ integrate((4*x^2+8*x+4)/(17*x^4+64*x^3+96*x^2+64*x+16),x,0,inf); This should give a division by zero error, and we enter debug mode: (dbm:1) :bt (dbm:1) I tried this with gcl, clisp, and cmucl. Nothing really seems to happen. Does debugmode work for anything? At least with CMUCL, it doesn't seem to matter too much, because I can press Cc to get to CMUCL's debugger which can then produce backtraces and such.  >Comment By: Robert Dodier (robert_dodier) Date: 20061105 09:11 Message: Logged In: YES user_id=501686 Maxima debugmode can print a backtrace of functions defined in Maxima by := . So far as I can tell, debugmode doesn't know anything about functions defined by defun or defmfun or defmspec. Given that most functions in Maxima are defined by defun, defmfun, and defmspec, it is not very informative to use debugmode. Since debugmode is useful in a certain context (namely debugging userdefined functions) I think we should keep it, but let's change "  an error. Quitting. To debug this try debugmode(true);" to just "  an error." (i.e. cut out the recommendation to use debugmode, which is usually not helpful, and also the "Quitting." because, in fact, Maxima is not executing (quit) nor quit()).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1590528&group_id=4933 
From: SourceForge.net <noreply@so...>  20061105 03:20:15

Bugs item #1575120, was opened at 20061011 01:54 Message generated for change (Comment added) made by sfrobot You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1575120&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Simplification Group: None >Status: Closed Resolution: Rejected Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Some laws are still missing Initial Comment: is(equal((x/y)^z,(x^z/y^z))); is(equal((x*y)^z,(x^z*y^z))); is(equal((x^y)^z,(x^(y*z)))); of course they are equal! Those are laws! Mario/Mexico  >Comment By: SourceForge Robot (sfrobot) Date: 20061104 19:20 Message: Logged In: YES user_id=1312539 This Tracker item was closed automatically by the system. It was previously set to a Pending status, and the original submitter did not respond within 14 days (the time period specified by the administrator of this Tracker).  Comment By: Robert Dodier (robert_dodier) Date: 20061021 13:26 Message: Logged In: YES user_id=501686 As mentioned by Barton, Maxima's default behavior is correct (since there are examples for which those equations fail to hold). I find that assuming x > 0 and y > 0, Maxima does evaluate those to true; I believe that is correct. assume(x>0,y>0); is(equal((x/y)^z,(x^z/y^z))); => true is(equal((x*y)^z,(x^z*y^z))); => true is(equal((x^y)^z,(x^(y*z)))); => true A possible enhancement (very far away at this point) would be for is(equal(...)) to return a result with one or more guard clauses specifying the applicability of various particular results. I won't try to spec that here. Marking this report "rejected" and "pending" (so that it will be closed automatically in 2 weeks, in case the original poster comes back).  Comment By: Barton Willis (willisbl) Date: 20061011 03:09 Message: Logged In: YES user_id=895922 For real x,y,z, the equation (x*y)^z = x^z*y^z isn't an identity. To see this, let x > 1, y > 1, and z > 1/2. If Maxima did is(equal((x*y)^z,(x^z*y^z))) > true that would be a bug. Similarly, all your other laws are not valid for all real numbers. (1) We're working on improving the function equal; it has many known problems. (2) The function 'radcan' does (%i16) radcan((x*y)^z); (%o16) x^z*y^z Maybe you would like to use it.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1575120&group_id=4933 
From: SourceForge.net <noreply@so...>  20061105 03:20:09

Bugs item #1572963, was opened at 20061007 17:06 Message generated for change (Comment added) made by sfrobot You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1572963&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None >Status: Closed Resolution: Wont Fix Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Inequalities bug Initial Comment: hi there is list bugs for maxima at: http://www.texsales.se/Artiklar/MaximaMuPAD.pdf#search=%22mupad%20vs%20maxima%22 I've personally checked this inequality: assume(x >= y, y >= z, z >= x)$ is( x = z ); I'm using maxima5.10.0.  >Comment By: SourceForge Robot (sfrobot) Date: 20061104 19:20 Message: Logged In: YES user_id=1312539 This Tracker item was closed automatically by the system. It was previously set to a Pending status, and the original submitter did not respond within 14 days (the time period specified by the administrator of this Tracker).  Comment By: Robert Dodier (robert_dodier) Date: 20061021 11:18 Message: Logged In: YES user_id=501686 x = z means x has the same structure as z. equal(x, z) means x is equivalent to z. assume(x >= y, y >= z, z >= x)$ is(equal(x, z)) yields true as one would hope. Marking this report "won't fix" and "pending" (so that it will be automatically closed in 2 weeks in case original poster comes back).  Comment By: Nobody/Anonymous (nobody) Date: 20061016 11:19 Message: Logged In: NO is(equal(a,b)); works. The distinction of "=" vs. "equal" is confusing  perhaps it should be revised for Maxima 6.0.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1572963&group_id=4933 
From: SourceForge.net <noreply@so...>  20061105 02:53:46

Bugs item #1582625, was opened at 20061023 00:22 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1582625&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core  Integration Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(t^2*log(t)/((t^21)*(t^4+1)), t, 0, 1) wrong? Initial Comment: Symbolic integration seems to return an incorrect result: (%i1) integrate(t^2*log(t)/((t^21)*(t^4+1)), t, 0, 1); (sqrt(2) + 1) %pi (%o1)  16 sqrt(2) (%i2) float(%); (%o2) 1.053029287545515 (%i3) romberg(t^2*log(t)/((t^21)*(t^4+1)), t, 0.0000001, 0.9999999); (%o3) 0.1806718095951 (%i4) float(%pi^2/(16*(2+sqrt(2)))); (%o4) 0.18067126259065  >Comment By: Raymond Toy (rtoy) Date: 20061104 21:53 Message: Logged In: YES user_id=28849 Fixed in defint.lisp as suggested.  Comment By: Raymond Toy (rtoy) Date: 20061103 16:40 Message: Logged In: YES user_id=28849 The issue appears to be in logimag02%pi. Some of the poles are of the form (1)^(1/4) or sqrt(%i). The call to simplify %plog(pole) doesn't actually simplify and the noun form is returned (I think). If we replace (defun logimag02%pi (x) (let ((plog (simplify ((%plog) ,x)))) with (defun logimag02%pi (x) (let ((plog (simplify ($rectform `((%plog) ,x))))) maxima returns (sqrt(2)2)*%pi^2/32 which is .1806712625906549, which corresponds pretty well with the numerical result from romberg and quad_qags. The test suite runs fine with this change. I think the real problem is in the simplifier for plog, but I'm not too motivated in fixing that.  Comment By: Raymond Toy (rtoy) Date: 20061023 13:57 Message: Logged In: YES user_id=28849 Maxima uses the substitution t = exp(y) to change the integral from 0 to 1 to 0 to inf. Then it uses its routine to handle this infinite integral by converting it to an integral from minf to inf, because the integrand is even. Finally, it uses rectzto%pi2 to integrate this final integrand. rectzto%pi2 needs to find the poles of the denominator. I'm guessing it's getting that wrong.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1582625&group_id=4933 