## [Maxima-bugs] [ maxima-Bugs-3511591 ] find_root

 [Maxima-bugs] [ maxima-Bugs-3511591 ] find_root From: SourceForge.net - 2012-03-27 01:32:12 ```Bugs item #3511591, was opened at 2012-03-26 16:26 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&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: nocod3 (nocod3) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: As you can see below the find_root fails, but it solves the polynomial resulting from the call to solve on the same expression??? (%i1) B:1000; (%o1) 1000 (%i2) I:75; (%o2) 75 (%i3) F:1200; (%o3) 1200 (%i4) n:10; (%o4) 10 (%i5) I/K*(1-1/(1+K)^n)+F/(1+K)^n -B; 1 75 (1 - ---------) 10 1200 (K + 1) (%o5) --------- + ------------------ - 1000 10 K (K + 1) (%i6) find_root(1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000, K, 0, 1); 1 75 (1 - ---------) 10 1200 (K + 1) (%o6) find_root(--------- + ------------------ - 1000, K, 0.0, 1.0) 10 K (K + 1) (%i7) solve([1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000], [K]); 10 9 8 7 6 5 4 (%o7) [0 = 40 K + 397 K + 1770 K + 4665 K + 8040 K + 9450 K + 7644 K 3 2 + 4170 K + 1440 K + 265 K - 38] (%i8) K:find_root(40*K^10+397*K^9+1770*K^8+4665*K^7+8040*K^6+9450*K^5+7644*K^4+4170*K^3+1440*K^2+265*K-38, K, 0, 1); (%o8) 0.0882729285301506 (%i9) I/K*(1-1/(1+K)^n)+F/(1+K)^n; (%o9) 999.9999999999998 (%i10) ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2012-03-26 18:32 Message: When pasting output, please use display2d:false first. Note that for your original equation in %o5, K=0 causes a division by zero. If you use find_root(%o5,K,1d-5,1), find_root returns a root. It would be nice if find_root gave some indication of why it failed, but that's a different issue. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&group_id=4933 ```

 [Maxima-bugs] [ maxima-Bugs-1632644 ] find_root From: SourceForge.net - 2007-01-10 19:04:24 ```Bugs item #1632644, was opened at 2007-01-10 13:04 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=1632644&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: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: It seems that find_root evaluates argument strangely: (%o6) x^2-1=0 (%i7) find_root(%,x,-5,5); Maxima encountered a Lisp error: The Lisp error is definitely a bug. Why should a user have to use find_root(''%,x,-5,5)? ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1632644&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1632644 ] find_root From: SourceForge.net - 2007-01-13 01:25:46 ```Bugs item #1632644, was opened at 2007-01-10 12:04 Message generated for change (Comment added) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1632644&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 - Solving equations Group: None >Status: Closed >Resolution: Duplicate Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: It seems that find_root evaluates argument strangely: (%o6) x^2-1=0 (%i7) find_root(%,x,-5,5); Maxima encountered a Lisp error: The Lisp error is definitely a bug. Why should a user have to use find_root(''%,x,-5,5)? ---------------------------------------------------------------------- >Comment By: Robert Dodier (robert_dodier) Date: 2007-01-12 18:25 Message: Logged In: YES user_id=501686 Originator: NO This item is a duplicate of bug report [ 1613390 ] find_root evaluates its arguments strangely. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1632644&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-3511591 ] find_root From: SourceForge.net - 2012-03-26 23:26:50 ```Bugs item #3511591, was opened at 2012-03-26 16:26 Message generated for change (Tracker Item Submitted) made by nocod3 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&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: nocod3 (nocod3) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: As you can see below the find_root fails, but it solves the polynomial resulting from the call to solve on the same expression??? (%i1) B:1000; (%o1) 1000 (%i2) I:75; (%o2) 75 (%i3) F:1200; (%o3) 1200 (%i4) n:10; (%o4) 10 (%i5) I/K*(1-1/(1+K)^n)+F/(1+K)^n -B; 1 75 (1 - ---------) 10 1200 (K + 1) (%o5) --------- + ------------------ - 1000 10 K (K + 1) (%i6) find_root(1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000, K, 0, 1); 1 75 (1 - ---------) 10 1200 (K + 1) (%o6) find_root(--------- + ------------------ - 1000, K, 0.0, 1.0) 10 K (K + 1) (%i7) solve([1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000], [K]); 10 9 8 7 6 5 4 (%o7) [0 = 40 K + 397 K + 1770 K + 4665 K + 8040 K + 9450 K + 7644 K 3 2 + 4170 K + 1440 K + 265 K - 38] (%i8) K:find_root(40*K^10+397*K^9+1770*K^8+4665*K^7+8040*K^6+9450*K^5+7644*K^4+4170*K^3+1440*K^2+265*K-38, K, 0, 1); (%o8) 0.0882729285301506 (%i9) I/K*(1-1/(1+K)^n)+F/(1+K)^n; (%o9) 999.9999999999998 (%i10) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-3511591 ] find_root From: SourceForge.net - 2012-03-27 01:32:12 ```Bugs item #3511591, was opened at 2012-03-26 16:26 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&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: nocod3 (nocod3) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: As you can see below the find_root fails, but it solves the polynomial resulting from the call to solve on the same expression??? (%i1) B:1000; (%o1) 1000 (%i2) I:75; (%o2) 75 (%i3) F:1200; (%o3) 1200 (%i4) n:10; (%o4) 10 (%i5) I/K*(1-1/(1+K)^n)+F/(1+K)^n -B; 1 75 (1 - ---------) 10 1200 (K + 1) (%o5) --------- + ------------------ - 1000 10 K (K + 1) (%i6) find_root(1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000, K, 0, 1); 1 75 (1 - ---------) 10 1200 (K + 1) (%o6) find_root(--------- + ------------------ - 1000, K, 0.0, 1.0) 10 K (K + 1) (%i7) solve([1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000], [K]); 10 9 8 7 6 5 4 (%o7) [0 = 40 K + 397 K + 1770 K + 4665 K + 8040 K + 9450 K + 7644 K 3 2 + 4170 K + 1440 K + 265 K - 38] (%i8) K:find_root(40*K^10+397*K^9+1770*K^8+4665*K^7+8040*K^6+9450*K^5+7644*K^4+4170*K^3+1440*K^2+265*K-38, K, 0, 1); (%o8) 0.0882729285301506 (%i9) I/K*(1-1/(1+K)^n)+F/(1+K)^n; (%o9) 999.9999999999998 (%i10) ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2012-03-26 18:32 Message: When pasting output, please use display2d:false first. Note that for your original equation in %o5, K=0 causes a division by zero. If you use find_root(%o5,K,1d-5,1), find_root returns a root. It would be nice if find_root gave some indication of why it failed, but that's a different issue. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-3511591 ] find_root From: SourceForge.net - 2012-03-27 02:23:27 ```Bugs item #3511591, was opened at 2012-03-26 16:26 Message generated for change (Comment added) made by nocod3 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&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: None Priority: 5 Private: No Submitted By: nocod3 (nocod3) Assigned to: Nobody/Anonymous (nobody) Summary: find_root Initial Comment: As you can see below the find_root fails, but it solves the polynomial resulting from the call to solve on the same expression??? (%i1) B:1000; (%o1) 1000 (%i2) I:75; (%o2) 75 (%i3) F:1200; (%o3) 1200 (%i4) n:10; (%o4) 10 (%i5) I/K*(1-1/(1+K)^n)+F/(1+K)^n -B; 1 75 (1 - ---------) 10 1200 (K + 1) (%o5) --------- + ------------------ - 1000 10 K (K + 1) (%i6) find_root(1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000, K, 0, 1); 1 75 (1 - ---------) 10 1200 (K + 1) (%o6) find_root(--------- + ------------------ - 1000, K, 0.0, 1.0) 10 K (K + 1) (%i7) solve([1200/(K+1)^10+(75*(1-1/(K+1)^10))/K-1000], [K]); 10 9 8 7 6 5 4 (%o7) [0 = 40 K + 397 K + 1770 K + 4665 K + 8040 K + 9450 K + 7644 K 3 2 + 4170 K + 1440 K + 265 K - 38] (%i8) K:find_root(40*K^10+397*K^9+1770*K^8+4665*K^7+8040*K^6+9450*K^5+7644*K^4+4170*K^3+1440*K^2+265*K-38, K, 0, 1); (%o8) 0.0882729285301506 (%i9) I/K*(1-1/(1+K)^n)+F/(1+K)^n; (%o9) 999.9999999999998 (%i10) ---------------------------------------------------------------------- >Comment By: nocod3 (nocod3) Date: 2012-03-26 19:23 Message: Ooouups, I apologize. Thanks for that. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2012-03-26 18:32 Message: When pasting output, please use display2d:false first. Note that for your original equation in %o5, K=0 causes a division by zero. If you use find_root(%o5,K,1d-5,1), find_root returns a root. It would be nice if find_root gave some indication of why it failed, but that's a different issue. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=3511591&group_id=4933 ```