You can subscribe to this list here.
2002 
_{Jan}

_{Feb}

_{Mar}

_{Apr}

_{May}

_{Jun}
(67) 
_{Jul}
(61) 
_{Aug}
(49) 
_{Sep}
(43) 
_{Oct}
(59) 
_{Nov}
(24) 
_{Dec}
(18) 

2003 
_{Jan}
(34) 
_{Feb}
(35) 
_{Mar}
(72) 
_{Apr}
(42) 
_{May}
(46) 
_{Jun}
(15) 
_{Jul}
(64) 
_{Aug}
(62) 
_{Sep}
(22) 
_{Oct}
(41) 
_{Nov}
(57) 
_{Dec}
(56) 
2004 
_{Jan}
(48) 
_{Feb}
(47) 
_{Mar}
(33) 
_{Apr}
(39) 
_{May}
(6) 
_{Jun}
(17) 
_{Jul}
(19) 
_{Aug}
(10) 
_{Sep}
(14) 
_{Oct}
(74) 
_{Nov}
(80) 
_{Dec}
(22) 
2005 
_{Jan}
(43) 
_{Feb}
(33) 
_{Mar}
(52) 
_{Apr}
(74) 
_{May}
(32) 
_{Jun}
(58) 
_{Jul}
(18) 
_{Aug}
(41) 
_{Sep}
(71) 
_{Oct}
(28) 
_{Nov}
(65) 
_{Dec}
(68) 
2006 
_{Jan}
(54) 
_{Feb}
(37) 
_{Mar}
(82) 
_{Apr}
(211) 
_{May}
(69) 
_{Jun}
(75) 
_{Jul}
(279) 
_{Aug}
(139) 
_{Sep}
(135) 
_{Oct}
(58) 
_{Nov}
(81) 
_{Dec}
(78) 
2007 
_{Jan}
(141) 
_{Feb}
(134) 
_{Mar}
(65) 
_{Apr}
(49) 
_{May}
(61) 
_{Jun}
(90) 
_{Jul}
(72) 
_{Aug}
(53) 
_{Sep}
(86) 
_{Oct}
(61) 
_{Nov}
(62) 
_{Dec}
(101) 
2008 
_{Jan}
(100) 
_{Feb}
(66) 
_{Mar}
(76) 
_{Apr}
(95) 
_{May}
(77) 
_{Jun}
(93) 
_{Jul}
(103) 
_{Aug}
(76) 
_{Sep}
(42) 
_{Oct}
(55) 
_{Nov}
(44) 
_{Dec}
(75) 
2009 
_{Jan}
(103) 
_{Feb}
(105) 
_{Mar}
(121) 
_{Apr}
(59) 
_{May}
(103) 
_{Jun}
(82) 
_{Jul}
(67) 
_{Aug}
(76) 
_{Sep}
(85) 
_{Oct}
(75) 
_{Nov}
(181) 
_{Dec}
(133) 
2010 
_{Jan}
(107) 
_{Feb}
(116) 
_{Mar}
(145) 
_{Apr}
(89) 
_{May}
(138) 
_{Jun}
(85) 
_{Jul}
(82) 
_{Aug}
(111) 
_{Sep}
(70) 
_{Oct}
(83) 
_{Nov}
(60) 
_{Dec}
(16) 
2011 
_{Jan}
(61) 
_{Feb}
(16) 
_{Mar}
(52) 
_{Apr}
(41) 
_{May}
(34) 
_{Jun}
(41) 
_{Jul}
(57) 
_{Aug}
(73) 
_{Sep}
(21) 
_{Oct}
(45) 
_{Nov}
(50) 
_{Dec}
(28) 
2012 
_{Jan}
(70) 
_{Feb}
(36) 
_{Mar}
(71) 
_{Apr}
(29) 
_{May}
(48) 
_{Jun}
(61) 
_{Jul}
(44) 
_{Aug}
(54) 
_{Sep}
(20) 
_{Oct}
(28) 
_{Nov}
(41) 
_{Dec}
(137) 
2013 
_{Jan}
(62) 
_{Feb}
(55) 
_{Mar}
(31) 
_{Apr}
(23) 
_{May}
(54) 
_{Jun}
(54) 
_{Jul}
(90) 
_{Aug}
(46) 
_{Sep}
(38) 
_{Oct}
(60) 
_{Nov}
(92) 
_{Dec}
(17) 
2014 
_{Jan}
(62) 
_{Feb}
(35) 
_{Mar}
(72) 
_{Apr}
(30) 
_{May}
(97) 
_{Jun}
(81) 
_{Jul}
(63) 
_{Aug}
(64) 
_{Sep}
(28) 
_{Oct}
(45) 
_{Nov}
(48) 
_{Dec}
(109) 
2015 
_{Jan}
(106) 
_{Feb}
(36) 
_{Mar}
(65) 
_{Apr}
(63) 
_{May}
(95) 
_{Jun}
(56) 
_{Jul}
(48) 
_{Aug}
(55) 
_{Sep}
(100) 
_{Oct}
(57) 
_{Nov}
(33) 
_{Dec}

S  M  T  W  T  F  S 

1

2

3
(3) 
4
(2) 
5
(1) 
6
(1) 
7
(4) 
8
(4) 
9
(6) 
10
(3) 
11
(4) 
12
(4) 
13
(4) 
14
(5) 
15
(5) 
16
(1) 
17

18

19
(4) 
20

21
(2) 
22

23
(1) 
24
(3) 
25

26
(4) 
27

28
(6) 
29

30

31
(3) 




From: SourceForge.net <noreply@so...>  20120109 19:37:17

Bugs item #3471450, was opened at 20120109 08:24 Message generated for change (Comment added) made by riotorto You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: Add ability to fill implicit functions. Initial Comment: Apologies if this is already possible, but I wish to fill the feasible region of a set of inequalities. I am able to plot the inequalities themselves, but I don't know a way to fill the feasible region (as far as i can see you can only fill explicit functions): Example: wxdraw2d( implicit(1*x + 2*y >=0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max), color = red, implicit(x = 0, x, g_min, g_max, y, g_min, g_max), implicit(y = 0, x, g_min, g_max, y, g_min, g_max) ); Thanks  >Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120109 11:37 Message: The algorithm is not smart enough in sharp corners. You have to fine tune the resolution with options x_voxel and y_voxel, as in this example: wxdraw2d( x_voxel = 70, y_voxel = 70, region(1*x + 2*y >=0 and 2*x + .5*y >=0 , x, g_min, g_max, y, g_min,g_max), implicit(1*x + 2*y = 0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y =0, x, g_min, g_max, y, g_min, g_max) ); default value for these options is 10, which may be too low resolution for many situations. Plotting time grows with resolution, of course. By the way, object 'implicit' doesn't take care of inequalities. Hope this helps.  Mario  Comment By: Edd Barrett (vext0101) Date: 20120109 10:02 Message: Great, but is there a bug (see attached image): g_min : 0; g_max : 100; wxdraw2d( region(1*x + 2*y >=0 and 2*x + .5*y >=0 , x, g_min, g_max, y, g_min, g_max), implicit(1*x + 2*y >= 0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max) ); Bottom left unfilled region is wrong? % pkg_info  grep maxima maxima5.25.1p3 GPL computer algebra system based on DOE Macsyma wxMaxima11.08.0p0 wxWidgets GUI for the computer algebra system maxima % pkg_info  grep gnuplot gnuplot4.4.3p3 commanddriven interactive function plotting program Cheers  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120109 09:44 Message: Hello, Try object 'region'. Take a look at some examples here: http://riotorto.users.sourceforge.net/gnuplot/region  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&group_id=4933 
From: SourceForge.net <noreply@so...>  20120109 18:02:13

Bugs item #3471450, was opened at 20120109 08:24 Message generated for change (Comment added) made by vext0101 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: Add ability to fill implicit functions. Initial Comment: Apologies if this is already possible, but I wish to fill the feasible region of a set of inequalities. I am able to plot the inequalities themselves, but I don't know a way to fill the feasible region (as far as i can see you can only fill explicit functions): Example: wxdraw2d( implicit(1*x + 2*y >=0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max), color = red, implicit(x = 0, x, g_min, g_max, y, g_min, g_max), implicit(y = 0, x, g_min, g_max, y, g_min, g_max) ); Thanks  >Comment By: Edd Barrett (vext0101) Date: 20120109 10:02 Message: Great, but is there a bug (see attached image): g_min : 0; g_max : 100; wxdraw2d( region(1*x + 2*y >=0 and 2*x + .5*y >=0 , x, g_min, g_max, y, g_min, g_max), implicit(1*x + 2*y >= 0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max) ); Bottom left unfilled region is wrong? % pkg_info  grep maxima maxima5.25.1p3 GPL computer algebra system based on DOE Macsyma wxMaxima11.08.0p0 wxWidgets GUI for the computer algebra system maxima % pkg_info  grep gnuplot gnuplot4.4.3p3 commanddriven interactive function plotting program Cheers  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120109 09:44 Message: Hello, Try object 'region'. Take a look at some examples here: http://riotorto.users.sourceforge.net/gnuplot/region  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&group_id=4933 
From: SourceForge.net <noreply@so...>  20120109 17:44:12

Bugs item #3471450, was opened at 20120109 08:24 Message generated for change (Comment added) made by riotorto You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: Add ability to fill implicit functions. Initial Comment: Apologies if this is already possible, but I wish to fill the feasible region of a set of inequalities. I am able to plot the inequalities themselves, but I don't know a way to fill the feasible region (as far as i can see you can only fill explicit functions): Example: wxdraw2d( implicit(1*x + 2*y >=0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max), color = red, implicit(x = 0, x, g_min, g_max, y, g_min, g_max), implicit(y = 0, x, g_min, g_max, y, g_min, g_max) ); Thanks  >Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120109 09:44 Message: Hello, Try object 'region'. Take a look at some examples here: http://riotorto.users.sourceforge.net/gnuplot/region  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&group_id=4933 
From: SourceForge.net <noreply@so...>  20120109 16:24:42

Bugs item #3471450, was opened at 20120109 08:24 Message generated for change (Tracker Item Submitted) made by vext0101 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: Add ability to fill implicit functions. Initial Comment: Apologies if this is already possible, but I wish to fill the feasible region of a set of inequalities. I am able to plot the inequalities themselves, but I don't know a way to fill the feasible region (as far as i can see you can only fill explicit functions): Example: wxdraw2d( implicit(1*x + 2*y >=0, x, g_min, g_max, y, g_min, g_max), implicit(2*x + .5*y >=0, x, g_min, g_max, y, g_min, g_max), color = red, implicit(x = 0, x, g_min, g_max, y, g_min, g_max), implicit(y = 0, x, g_min, g_max, y, g_min, g_max) ); Thanks  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3471450&group_id=4933 
From: SourceForge.net <noreply@so...>  20120109 14:38:26

Bugs item #3470668, was opened at 20120107 11:03 Message generated for change (Comment added) made by aleksasd You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&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: bemdev (bemdev77) Assigned to: Nobody/Anonymous (nobody) Summary: Integration is not correct: invalid 'false' term in results Initial Comment: I try to run following Maxima code: assume(a > 0); assume(b > 0); assume(4*a*c > 1); f : x^4 / (a*x^2 + x + c)^(5/2); integrate(f, x); But result is strange. There is invalid "9*false" term in results.  Comment By: Aleksas (aleksasd) Date: 20120109 06:38 Message: Problem. integrate(x^4 / (a*x^2 + x + c)^(5/2),x), a > 0, b > 0, 4*a*c1 > 0. We solve with steps. All is OK. Output is removed(to large) (%i1) assume(a > 0, b > 0, 4*a*c1 > 0); (%i2) f : x^4 / (a*x^2 + x + c)^(5/2)$ (%i3) S:'integrate(f, x); (%i4) a*x^2 + x + c=a*(x+1/(2*a))^21/(4*a)+c; (%i5) S1:changevar(S, y=x+1/(2*a), y, x); (%i6) part(S1,1,1)=partfrac(part(S1,1,1),y); (%i7) subst(%,S1); (%i8) ev(%, nouns); Solution: (%i9) sol:subst(y=x+1/(2*a),%); Test of solution: (%i10) diff(sol,x)f$ (%i11) radcan(%);  Comment By: Barton Willis (willisbl) Date: 20120108 11:03 Message: The source code comment for nummdenn indicates that Maxima should handle this antiderivative.  Comment By: Barton Willis (willisbl) Date: 20120108 06:31 Message: The function distrint (defined in irinte.lisp) tries to integrate each member of a list using the function intira. When intira fails to find an antiderivative, it returns nil. Either distrint needs to be modified to look for nil, or intira fails when it should not. Changing distrint to (defun distrint (l x) (addn (mapcar #'(lambda (e) (let ((ie (intira e x))) (if ie ie `((%integrate simp) ,e ,x)))) l) t)) allows Maxima to return a nounform for x^4 / (a*x^2 + x + c)^(5/2).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&group_id=4933 
From: SourceForge.net <noreply@so...>  20120108 21:44:24

Bugs item #3470669, was opened at 20120107 11:07 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&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  Assume Group: None Status: Pending Resolution: Works For Me Priority: 5 Private: No Submitted By: Bjørn (storebjoern) Assigned to: Nobody/Anonymous (nobody) Summary: assume(...)$ can't be reworked Initial Comment: I have problems to investigate formulas, because e.g. the statement "assume (r > 1)" can't be overwritten by a statement "assume (r < 1)" Example: 1,step Writing assume (r > 1)$ integrate (1/x+r,x,1,r); results in log(r)+r^2r 2. step Adding new lines (or modifying asumeline from 1. step) assume (r < 1)$ integrate (1/x+r,x,1,r); still results in log(r)+r^2r 3. step Whereas assume (a < 1)$ integrate (1/x+a,x,1,a); results in the question "Is "a" positive, negative, or zero?"  >Comment By: Raymond Toy (rtoy) Date: 20120108 13:44 Message: There are lots of bugs caused by the assume database. But new users also shouldn't be suppressing the output of commands. I'm not sure what you expect maxima to do when given inconsistent facts. It did say inconsistent, but you suppressed the output. Perhaps maxima should signal an error for inconsistent assumptions? Then people would complain about the error message.  Comment By: Bjørn (storebjoern) Date: 20120107 14:54 Message: Got it  thank you. Have you maybe some idea to make the assume/factsdesign more handy? I could imagine, that some of the open bugs are related to the current chewy "assume" behaviour. Also new user may be frustrated using the system after such unexpected behaviour and without any comment will be gone forever.  Comment By: Viktor Toth (vttoth) Date: 20120107 12:37 Message: There do not seem to be any bugs here. The second assume() fails with [inconsistent], which the user missed as output was suppressed (using $ instead of ; as a line terminator). A previous assumption can be discarded using forget(). As to the third issue, knowing that a<1 does not tell Maxima if a is positive, negative, or zero, so the question is warranted. In short: (%i1) display2d:false; (%o1) false (%i2) assume(r>1); (%o2) [r > 1] (%i3) integrate(1/x+r,x,1,r); (%o3) log(r)+r^2r (%i4) assume(r<1); (%o4) [inconsistent] (%i5) forget(r>1); (%o5) [r > 1] (%i6) assume(r<1); (%o6) [r < 1] (%i7) integrate(1/x+r,x,1,r); Is r positive, negative, or zero? pos; (%o7) log(r)+r^2r (%i8) assume(a<0); (%o8) [a < 0] (%i9) integrate(1/x+a,x,1,a); Principal Value (%o9) log(a)+a^2alog(1)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&group_id=4933 
From: SourceForge.net <noreply@so...>  20120108 19:03:21

Bugs item #3470668, was opened at 20120107 11:03 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&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: bemdev (bemdev77) Assigned to: Nobody/Anonymous (nobody) Summary: Integration is not correct: invalid 'false' term in results Initial Comment: I try to run following Maxima code: assume(a > 0); assume(b > 0); assume(4*a*c > 1); f : x^4 / (a*x^2 + x + c)^(5/2); integrate(f, x); But result is strange. There is invalid "9*false" term in results.  >Comment By: Barton Willis (willisbl) Date: 20120108 11:03 Message: The source code comment for nummdenn indicates that Maxima should handle this antiderivative.  Comment By: Barton Willis (willisbl) Date: 20120108 06:31 Message: The function distrint (defined in irinte.lisp) tries to integrate each member of a list using the function intira. When intira fails to find an antiderivative, it returns nil. Either distrint needs to be modified to look for nil, or intira fails when it should not. Changing distrint to (defun distrint (l x) (addn (mapcar #'(lambda (e) (let ((ie (intira e x))) (if ie ie `((%integrate simp) ,e ,x)))) l) t)) allows Maxima to return a nounform for x^4 / (a*x^2 + x + c)^(5/2).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&group_id=4933 
From: SourceForge.net <noreply@so...>  20120108 14:31:08

Bugs item #3470668, was opened at 20120107 11:03 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&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: bemdev (bemdev77) Assigned to: Nobody/Anonymous (nobody) Summary: Integration is not correct: invalid 'false' term in results Initial Comment: I try to run following Maxima code: assume(a > 0); assume(b > 0); assume(4*a*c > 1); f : x^4 / (a*x^2 + x + c)^(5/2); integrate(f, x); But result is strange. There is invalid "9*false" term in results.  >Comment By: Barton Willis (willisbl) Date: 20120108 06:31 Message: The function distrint (defined in irinte.lisp) tries to integrate each member of a list using the function intira. When intira fails to find an antiderivative, it returns nil. Either distrint needs to be modified to look for nil, or intira fails when it should not. Changing distrint to (defun distrint (l x) (addn (mapcar #'(lambda (e) (let ((ie (intira e x))) (if ie ie `((%integrate simp) ,e ,x)))) l) t)) allows Maxima to return a nounform for x^4 / (a*x^2 + x + c)^(5/2).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&group_id=4933 
From: SourceForge.net <noreply@so...>  20120108 00:22:12

Bugs item #3470669, was opened at 20120107 11:07 Message generated for change (Settings changed) made by vttoth You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&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  Assume Group: None >Status: Pending Resolution: Works For Me Priority: 5 Private: No Submitted By: Bjørn (storebjoern) Assigned to: Nobody/Anonymous (nobody) Summary: assume(...)$ can't be reworked Initial Comment: I have problems to investigate formulas, because e.g. the statement "assume (r > 1)" can't be overwritten by a statement "assume (r < 1)" Example: 1,step Writing assume (r > 1)$ integrate (1/x+r,x,1,r); results in log(r)+r^2r 2. step Adding new lines (or modifying asumeline from 1. step) assume (r < 1)$ integrate (1/x+r,x,1,r); still results in log(r)+r^2r 3. step Whereas assume (a < 1)$ integrate (1/x+a,x,1,a); results in the question "Is "a" positive, negative, or zero?"  Comment By: Bjørn (storebjoern) Date: 20120107 14:54 Message: Got it  thank you. Have you maybe some idea to make the assume/factsdesign more handy? I could imagine, that some of the open bugs are related to the current chewy "assume" behaviour. Also new user may be frustrated using the system after such unexpected behaviour and without any comment will be gone forever.  Comment By: Viktor Toth (vttoth) Date: 20120107 12:37 Message: There do not seem to be any bugs here. The second assume() fails with [inconsistent], which the user missed as output was suppressed (using $ instead of ; as a line terminator). A previous assumption can be discarded using forget(). As to the third issue, knowing that a<1 does not tell Maxima if a is positive, negative, or zero, so the question is warranted. In short: (%i1) display2d:false; (%o1) false (%i2) assume(r>1); (%o2) [r > 1] (%i3) integrate(1/x+r,x,1,r); (%o3) log(r)+r^2r (%i4) assume(r<1); (%o4) [inconsistent] (%i5) forget(r>1); (%o5) [r > 1] (%i6) assume(r<1); (%o6) [r < 1] (%i7) integrate(1/x+r,x,1,r); Is r positive, negative, or zero? pos; (%o7) log(r)+r^2r (%i8) assume(a<0); (%o8) [a < 0] (%i9) integrate(1/x+a,x,1,a); Principal Value (%o9) log(a)+a^2alog(1)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&group_id=4933 
From: SourceForge.net <noreply@so...>  20120107 22:54:11

Bugs item #3470669, was opened at 20120107 11:07 Message generated for change (Comment added) made by storebjoern You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&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  Assume Group: None >Status: Open Resolution: Works For Me Priority: 5 Private: No Submitted By: Bjørn (storebjoern) Assigned to: Nobody/Anonymous (nobody) Summary: assume(...)$ can't be reworked Initial Comment: I have problems to investigate formulas, because e.g. the statement "assume (r > 1)" can't be overwritten by a statement "assume (r < 1)" Example: 1,step Writing assume (r > 1)$ integrate (1/x+r,x,1,r); results in log(r)+r^2r 2. step Adding new lines (or modifying asumeline from 1. step) assume (r < 1)$ integrate (1/x+r,x,1,r); still results in log(r)+r^2r 3. step Whereas assume (a < 1)$ integrate (1/x+a,x,1,a); results in the question "Is "a" positive, negative, or zero?"  >Comment By: Bjørn (storebjoern) Date: 20120107 14:54 Message: Got it  thank you. Have you maybe some idea to make the assume/factsdesign more handy? I could imagine, that some of the open bugs are related to the current chewy "assume" behaviour. Also new user may be frustrated using the system after such unexpected behaviour and without any comment will be gone forever.  Comment By: Viktor Toth (vttoth) Date: 20120107 12:37 Message: There do not seem to be any bugs here. The second assume() fails with [inconsistent], which the user missed as output was suppressed (using $ instead of ; as a line terminator). A previous assumption can be discarded using forget(). As to the third issue, knowing that a<1 does not tell Maxima if a is positive, negative, or zero, so the question is warranted. In short: (%i1) display2d:false; (%o1) false (%i2) assume(r>1); (%o2) [r > 1] (%i3) integrate(1/x+r,x,1,r); (%o3) log(r)+r^2r (%i4) assume(r<1); (%o4) [inconsistent] (%i5) forget(r>1); (%o5) [r > 1] (%i6) assume(r<1); (%o6) [r < 1] (%i7) integrate(1/x+r,x,1,r); Is r positive, negative, or zero? pos; (%o7) log(r)+r^2r (%i8) assume(a<0); (%o8) [a < 0] (%i9) integrate(1/x+a,x,1,a); Principal Value (%o9) log(a)+a^2alog(1)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&group_id=4933 
From: SourceForge.net <noreply@so...>  20120107 20:37:00

Bugs item #3470669, was opened at 20120107 11:07 Message generated for change (Comment added) made by vttoth You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&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  Assume Group: None >Status: Pending >Resolution: Works For Me Priority: 5 Private: No Submitted By: Bjørn (storebjoern) Assigned to: Nobody/Anonymous (nobody) Summary: assume(...)$ can't be reworked Initial Comment: I have problems to investigate formulas, because e.g. the statement "assume (r > 1)" can't be overwritten by a statement "assume (r < 1)" Example: 1,step Writing assume (r > 1)$ integrate (1/x+r,x,1,r); results in log(r)+r^2r 2. step Adding new lines (or modifying asumeline from 1. step) assume (r < 1)$ integrate (1/x+r,x,1,r); still results in log(r)+r^2r 3. step Whereas assume (a < 1)$ integrate (1/x+a,x,1,a); results in the question "Is "a" positive, negative, or zero?"  >Comment By: Viktor Toth (vttoth) Date: 20120107 12:37 Message: There do not seem to be any bugs here. The second assume() fails with [inconsistent], which the user missed as output was suppressed (using $ instead of ; as a line terminator). A previous assumption can be discarded using forget(). As to the third issue, knowing that a<1 does not tell Maxima if a is positive, negative, or zero, so the question is warranted. In short: (%i1) display2d:false; (%o1) false (%i2) assume(r>1); (%o2) [r > 1] (%i3) integrate(1/x+r,x,1,r); (%o3) log(r)+r^2r (%i4) assume(r<1); (%o4) [inconsistent] (%i5) forget(r>1); (%o5) [r > 1] (%i6) assume(r<1); (%o6) [r < 1] (%i7) integrate(1/x+r,x,1,r); Is r positive, negative, or zero? pos; (%o7) log(r)+r^2r (%i8) assume(a<0); (%o8) [a < 0] (%i9) integrate(1/x+a,x,1,a); Principal Value (%o9) log(a)+a^2alog(1)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&group_id=4933 
From: SourceForge.net <noreply@so...>  20120107 19:07:07

Bugs item #3470669, was opened at 20120107 11:07 Message generated for change (Tracker Item Submitted) made by storebjoern You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&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  Assume Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Bjørn (storebjoern) Assigned to: Nobody/Anonymous (nobody) Summary: assume(...)$ can't be reworked Initial Comment: I have problems to investigate formulas, because e.g. the statement "assume (r > 1)" can't be overwritten by a statement "assume (r < 1)" Example: 1,step Writing assume (r > 1)$ integrate (1/x+r,x,1,r); results in log(r)+r^2r 2. step Adding new lines (or modifying asumeline from 1. step) assume (r < 1)$ integrate (1/x+r,x,1,r); still results in log(r)+r^2r 3. step Whereas assume (a < 1)$ integrate (1/x+a,x,1,a); results in the question "Is "a" positive, negative, or zero?"  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470669&group_id=4933 
From: SourceForge.net <noreply@so...>  20120107 19:03:40

Bugs item #3470668, was opened at 20120107 11:03 Message generated for change (Tracker Item Submitted) made by bemdev77 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&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: bemdev (bemdev77) Assigned to: Nobody/Anonymous (nobody) Summary: Integration is not correct: invalid 'false' term in results Initial Comment: I try to run following Maxima code: assume(a > 0); assume(b > 0); assume(4*a*c > 1); f : x^4 / (a*x^2 + x + c)^(5/2); integrate(f, x); But result is strange. There is invalid "9*false" term in results.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470668&group_id=4933 
From: SourceForge.net <noreply@so...>  20120106 18:16:55

Bugs item #3470385, was opened at 20120106 10:16 Message generated for change (Tracker Item Submitted) made by woollett You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470385&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: Open Resolution: None Priority: 5 Private: No Submitted By: Ted Woollett (woollett) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(exp(sqrt)) gcl bug Initial Comment: In the git notes for the new version of defint.lisp, Dan Gildea has the comment:  integrate(exp(sqrt(x^3)),x,0,1) no longer gives correct answer unless we specify radexpand:false  I find (gcl) that the previous version of defint.lisp gives the correct integral with radexpand : true (default).  Maxima 5.25.1 http://maxima.sourceforge.net using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (a.k.a. GCL) (%i1) first(quad_qags(exp(sqrt(x^3)),x,0,1)); (%o1) 1.562394062214541 /* v 5.25.1 defint.lisp and radexpand=true */ (%i2) radexpand; (%o2) true (%i3) integrate(exp(sqrt(x^3)),x,0,1); (%o3) (sqrt(3)*%i+1)*(gamma(2/3)gamma_incomplete(2/3,1))/3 (%i4) expand(float(%)); (%o4) 1.5623940622173124.4408920985006262E16*%i /* ok except for roundoff errors */  When I load in the new version of defint.lisp, and leave radexpand : true I get an answer, albeit a wrong answer. But if I set radexpand to false, I only get a noun form.  (%i5) load("defintnew.lisp"); (%o5) "c:/work2/defintnew.lisp" (%i6) radexpand; (%o6) true /* with new defint.lisp and radexpand=true */ (%i7) integrate(exp(sqrt(x^3)),x,0,1); (%o7) 2*(gamma(2/3)gamma_incomplete(2/3,1))/3 (%i8) expand(float(%)); (%o8) 1.353072948602157*%i0.78119703110866 /* which is a wrong answer as advertised . */ /* now set radexpand to false */ (%i9) radexpand:false$ (%i10) integrate(exp(sqrt(x^3)),x,0,1); (%o10) 'integrate(%e^sqrt(x^3),x,0,1) /* unexpected noun form */  Ted Woollett Maxima version: 5.25.1 Maxima build date: 10:2 9/6/2011 Host type: i686pcmingw32 Lisp implementation type: GNU Common Lisp (GCL) Lisp implementation version: GCL 2.6.8  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3470385&group_id=4933 
From: SourceForge.net <noreply@so...>  20120105 15:12:17

Bugs item #3459556, was opened at 20111214 09:11 Message generated for change (Comment added) made by riotorto You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&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: Fixed Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: draw3d of z=0: there is no surface in a draw3d range Initial Comment: Consider this function: convex_env(u_l, u_h, v_l, v_h, z_l, z_h) := wxdraw3d( xrange = [u_l, u_h], yrange = [v_l, v_h], zrange = [z_l, z_h], implicit( z=((v_l*v)  (u_l*u) + (u_l*v_l)), u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) )$ Most applications of this function yield a surface, however, sometimes the result is a single point and maxima bails out. Eg: convex_env(0, 2, 0, 2, 0, 2); gives: draw3d (implicit): no surface within these ranges. Infact it is the same as plotting: implicit( z=0, u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) Is z=0 not a surface within z=[0, 2]? I get the same when drawing z=0.1, but not for z=0.2. Is this correct ?  >Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120105 07:12 Message: Thanks for your comments.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120105 07:12 Message: The reported bug is not present in the current cvs version of Maxima. Thank you for your report. If you see this bug in a later version of Maxima, please submit a new bug report.  Comment By: Edd Barrett (vext0101) Date: 20120104 05:12 Message: Looks good. Previously,' wxdraw3d(implicit(z=0, u, 0, 2, v, 0, 2, z, 0, 2))' would fail, but with the new grcommon, the plot draws as expected. Thanks, I will backport this into the OpenBSD package. Many thanks.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120103 11:49 Message: Download grcommon.lisp from folder share/draw in the repository and place it in your local tree. Try it and let me know if it works as expected.  Mario  Comment By: Edd Barrett (vext0101) Date: 20120103 08:32 Message: Any news on this? Cheers.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20111215 00:17 Message: Hello, I'll take a look at this. In the meantime, you can consider if the following workaround, or something similar, fits your needs: convex_env(ul, uh, vl, vh, zl, zh) := wxdraw3d( xrange = [ul, uh], yrange = [vl, vh], zrange = [zl, zh], implicit( z=((vl*v)  (ul*u) + (ul*vl)), u, ul0.1, uh+0.1, v ,vl0.1, vh+0.1, z, zl0.1, zh+0.1 ) )$  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&group_id=4933 
From: SourceForge.net <noreply@so...>  20120104 16:17:47

Bugs item #3469184, was opened at 20120103 11:45 Message generated for change (Comment added) made by dgildea You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3469184&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: Fixed Priority: 5 Private: No Submitted By: Ted Woollett (woollett) >Assigned to: Dan Gildea (dgildea) Summary: integrate(exp(x^n),x,0,1) bug for n >2 Initial Comment: the definite integral of the real function exp(x^n) over the real interval (0,1) is broken (spurious imaginary parts, wrong real parts) for n = 3 through 15, and probably forever.  (%i1) exp_test(n) := ( print (n," qags = ", first( quad_qags (exp(x^n),x,0,1)), " integrate = ", expand(float(rectform(integrate(exp(x^n),x,0,1))))))$ (%i2) for m thru 15 do exp_test(m)$ 1 qags = 0.63212055882856 integrate = 0.63212055882856 2 qags = 0.74682413281243 integrate = 0.74682413281243 3 qags = 0.80751118213967 integrate = 0.69932519757296*%i0.40375559106984 4 qags = 0.8448385947571 integrate = 0.8448385947571*%i 5 qags = 0.87007466768589 integrate = 0.82749018236601*%i+0.26886785869008 6 qags = 0.88826369875194 integrate = 0.76925892837871*%i+0.44413184937597 7 qags = 0.90199160301324 integrate = 0.70520543215755*%i+0.56238256584096 8 qags = 0.91271857185875 integrate = 0.64538949147622*%i+0.64538949147622 9 qags = 0.9213308364909 integrate = 0.59222004611848*%i+0.70578036756801 10 qags = 0.92839720283799 integrate = 0.54569818409775*%i+0.7510891146261 11 qags = 0.93429939205577 integrate = 0.5051203870693*%i+0.78598266428894 12 qags = 0.93930307080183 integrate = 0.46965153540091*%i+0.81346032116712 13 qags = 0.94359882032526 integrate = 0.43851223691831*%i+0.83551526125626 14 qags = 0.94732690220079 integrate = 0.41102973849353*%i+0.85351204660935 15 qags = 0.95059283193 integrate = 0.38664093739113*%i+0.86840976367727  Maxima version: 5.25.1 Maxima build date: 10:2 9/6/2011 Host type: i686pcmingw32 Lisp implementation type: GNU Common Lisp (GCL) Lisp implementation version: GCL 2.6.8 Ted Woollett  >Comment By: Dan Gildea (dgildea) Date: 20120104 08:17 Message: Fixed in defint.lisp. intcv: check that we have correct root at both lower limit and upper limit  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3469184&group_id=4933 
From: SourceForge.net <noreply@so...>  20120104 13:12:15

Bugs item #3459556, was opened at 20111214 09:11 Message generated for change (Comment added) made by vext0101 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&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: Open >Resolution: Fixed Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: draw3d of z=0: there is no surface in a draw3d range Initial Comment: Consider this function: convex_env(u_l, u_h, v_l, v_h, z_l, z_h) := wxdraw3d( xrange = [u_l, u_h], yrange = [v_l, v_h], zrange = [z_l, z_h], implicit( z=((v_l*v)  (u_l*u) + (u_l*v_l)), u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) )$ Most applications of this function yield a surface, however, sometimes the result is a single point and maxima bails out. Eg: convex_env(0, 2, 0, 2, 0, 2); gives: draw3d (implicit): no surface within these ranges. Infact it is the same as plotting: implicit( z=0, u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) Is z=0 not a surface within z=[0, 2]? I get the same when drawing z=0.1, but not for z=0.2. Is this correct ?  >Comment By: Edd Barrett (vext0101) Date: 20120104 05:12 Message: Looks good. Previously,' wxdraw3d(implicit(z=0, u, 0, 2, v, 0, 2, z, 0, 2))' would fail, but with the new grcommon, the plot draws as expected. Thanks, I will backport this into the OpenBSD package. Many thanks.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120103 11:49 Message: Download grcommon.lisp from folder share/draw in the repository and place it in your local tree. Try it and let me know if it works as expected.  Mario  Comment By: Edd Barrett (vext0101) Date: 20120103 08:32 Message: Any news on this? Cheers.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20111215 00:17 Message: Hello, I'll take a look at this. In the meantime, you can consider if the following workaround, or something similar, fits your needs: convex_env(ul, uh, vl, vh, zl, zh) := wxdraw3d( xrange = [ul, uh], yrange = [vl, vh], zrange = [zl, zh], implicit( z=((vl*v)  (ul*u) + (ul*vl)), u, ul0.1, uh+0.1, v ,vl0.1, vh+0.1, z, zl0.1, zh+0.1 ) )$  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&group_id=4933 
From: SourceForge.net <noreply@so...>  20120103 19:49:57

Bugs item #3459556, was opened at 20111214 09:11 Message generated for change (Comment added) made by riotorto You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: draw3d of z=0: there is no surface in a draw3d range Initial Comment: Consider this function: convex_env(u_l, u_h, v_l, v_h, z_l, z_h) := wxdraw3d( xrange = [u_l, u_h], yrange = [v_l, v_h], zrange = [z_l, z_h], implicit( z=((v_l*v)  (u_l*u) + (u_l*v_l)), u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) )$ Most applications of this function yield a surface, however, sometimes the result is a single point and maxima bails out. Eg: convex_env(0, 2, 0, 2, 0, 2); gives: draw3d (implicit): no surface within these ranges. Infact it is the same as plotting: implicit( z=0, u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) Is z=0 not a surface within z=[0, 2]? I get the same when drawing z=0.1, but not for z=0.2. Is this correct ?  >Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20120103 11:49 Message: Download grcommon.lisp from folder share/draw in the repository and place it in your local tree. Try it and let me know if it works as expected.  Mario  Comment By: Edd Barrett (vext0101) Date: 20120103 08:32 Message: Any news on this? Cheers.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20111215 00:17 Message: Hello, I'll take a look at this. In the meantime, you can consider if the following workaround, or something similar, fits your needs: convex_env(ul, uh, vl, vh, zl, zh) := wxdraw3d( xrange = [ul, uh], yrange = [vl, vh], zrange = [zl, zh], implicit( z=((vl*v)  (ul*u) + (ul*vl)), u, ul0.1, uh+0.1, v ,vl0.1, vh+0.1, z, zl0.1, zh+0.1 ) )$  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&group_id=4933 
From: SourceForge.net <noreply@so...>  20120103 19:45:41

Bugs item #3469184, was opened at 20120103 11:45 Message generated for change (Tracker Item Submitted) made by woollett You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3469184&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: Open Resolution: None Priority: 5 Private: No Submitted By: Ted Woollett (woollett) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(exp(x^n),x,0,1) bug for n >2 Initial Comment: the definite integral of the real function exp(x^n) over the real interval (0,1) is broken (spurious imaginary parts, wrong real parts) for n = 3 through 15, and probably forever.  (%i1) exp_test(n) := ( print (n," qags = ", first( quad_qags (exp(x^n),x,0,1)), " integrate = ", expand(float(rectform(integrate(exp(x^n),x,0,1))))))$ (%i2) for m thru 15 do exp_test(m)$ 1 qags = 0.63212055882856 integrate = 0.63212055882856 2 qags = 0.74682413281243 integrate = 0.74682413281243 3 qags = 0.80751118213967 integrate = 0.69932519757296*%i0.40375559106984 4 qags = 0.8448385947571 integrate = 0.8448385947571*%i 5 qags = 0.87007466768589 integrate = 0.82749018236601*%i+0.26886785869008 6 qags = 0.88826369875194 integrate = 0.76925892837871*%i+0.44413184937597 7 qags = 0.90199160301324 integrate = 0.70520543215755*%i+0.56238256584096 8 qags = 0.91271857185875 integrate = 0.64538949147622*%i+0.64538949147622 9 qags = 0.9213308364909 integrate = 0.59222004611848*%i+0.70578036756801 10 qags = 0.92839720283799 integrate = 0.54569818409775*%i+0.7510891146261 11 qags = 0.93429939205577 integrate = 0.5051203870693*%i+0.78598266428894 12 qags = 0.93930307080183 integrate = 0.46965153540091*%i+0.81346032116712 13 qags = 0.94359882032526 integrate = 0.43851223691831*%i+0.83551526125626 14 qags = 0.94732690220079 integrate = 0.41102973849353*%i+0.85351204660935 15 qags = 0.95059283193 integrate = 0.38664093739113*%i+0.86840976367727  Maxima version: 5.25.1 Maxima build date: 10:2 9/6/2011 Host type: i686pcmingw32 Lisp implementation type: GNU Common Lisp (GCL) Lisp implementation version: GCL 2.6.8 Ted Woollett  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3469184&group_id=4933 
From: SourceForge.net <noreply@so...>  20120103 16:32:35

Bugs item #3459556, was opened at 20111214 09:11 Message generated for change (Comment added) made by vext0101 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&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: Open Resolution: None Priority: 5 Private: No Submitted By: Edd Barrett (vext0101) Assigned to: Nobody/Anonymous (nobody) Summary: draw3d of z=0: there is no surface in a draw3d range Initial Comment: Consider this function: convex_env(u_l, u_h, v_l, v_h, z_l, z_h) := wxdraw3d( xrange = [u_l, u_h], yrange = [v_l, v_h], zrange = [z_l, z_h], implicit( z=((v_l*v)  (u_l*u) + (u_l*v_l)), u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) )$ Most applications of this function yield a surface, however, sometimes the result is a single point and maxima bails out. Eg: convex_env(0, 2, 0, 2, 0, 2); gives: draw3d (implicit): no surface within these ranges. Infact it is the same as plotting: implicit( z=0, u, u_l, u_h, v, v_l, v_h, z, z_l, z_h ) Is z=0 not a surface within z=[0, 2]? I get the same when drawing z=0.1, but not for z=0.2. Is this correct ?  >Comment By: Edd Barrett (vext0101) Date: 20120103 08:32 Message: Any news on this? Cheers.  Comment By: Mario Rodriguez Riotorto (riotorto) Date: 20111215 00:17 Message: Hello, I'll take a look at this. In the meantime, you can consider if the following workaround, or something similar, fits your needs: convex_env(ul, uh, vl, vh, zl, zh) := wxdraw3d( xrange = [ul, uh], yrange = [vl, vh], zrange = [zl, zh], implicit( z=((vl*v)  (ul*u) + (ul*vl)), u, ul0.1, uh+0.1, v ,vl0.1, vh+0.1, z, zl0.1, zh+0.1 ) )$  Mario  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3459556&group_id=4933 