PTPTQUOTIENT: Polynomial quotient is not exact

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:04 Created by thunk06 on 2017-09-30 18:35:40 Original: https://sourceforge.net/p/maxima/bugs/3335

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Sorry for such huge expression but I have not yet tried to simplify it

rat( expr ) ratsimp( expr ) fullratsimp( expr ) are all returning the foillowing error message

                              PTPTQUOTIENT: Polynomial quotient is not exact

expr : ((2*(GM_N+GMBS_N+GDS_N)+GDS_E)*GM_P-((C_COMP*GDS_N*GM_F-(2*GDS_P+GDS_N))*GM_N+C_COMP*GDS_N*(GMBS_N+GDS_N)*GM_F)+(2*GDS_P+GDS_N)*GMBS_N+(2*GDS_N+GDS_E)*GDS_P+GDS_N*(GDS_N+GDS_E))/(GM_F*((2*(GM_N+GMBS_N+GDS_N)+GDS_E)*GM_P+(2*GDS_P+GDS_N)*(GM_N+GMBS_N)+(2*GDS_N+GDS_E)*GDS_P+GDS_N*(GDS_N+GDS_E)))+(GDS_F*((2*(C_COMP*(GDS_P+GDS_N)+1)*(GM_N+GMBS_N)+C_COMP*(2*GDS_N+GDS_E)*GDS_P+GDS_N*(C_COMP*(2*GDS_N+GDS_E)+2)+GDS_E)*GM_P+(2*GDS_P*(C_COMP*(GDS_P+GDS_N)+1)+GDS_N)*(GM_N+GMBS_N)+GDS_P*(C_COMP*(2*GDS_N+GDS_E)*GDS_P+2*GDS_N*(C_COMP*(GDS_N+GDS_E)+1)+GDS_E)+GDS_N*((C_COMP*GDS_E+1)*GDS_N+GDS_E))*(GDS_F*(2*(GM_N+GMBS_N+GDS_N)+GDS_E)*GM_P+(GDS_N*GM_F+GDS_F*(2*GDS_P+GDS_N))*GM_N+GDS_N*(GMBS_N+GDS_N+GDS_E)*GM_F+GDS_F*((2*GDS_P+GDS_N)*GMBS_N+(2*GDS_N+GDS_E)*GDS_P+GDS_N*(GDS_N+GDS_E))))/((GDS_P+GDS_N)*(2*(GM_N+GMBS_N+GDS_N)+GDS_E)*(GM_P+GDS_P)*(GDS_F*GM_F*((2*(GM_N+GMBS_N+GDS_N)+GDS_E)*GM_P+(2*GDS_P+GDS_N)*(GM_N+GMBS_N)+(2*GDS_N+GDS_E)*GDS_P+GDS_N*(GDS_N+GDS_E)))) ;

Regards, Jacques

PS: The only workaround I found yet is to first call factor( expr ) before rat ratsimp fullratsimp

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:05 Created by tomasriker on 2017-10-03 19:47:48 Original: https://sourceforge.net/p/maxima/bugs/3335/#61ba

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Corrected formatting

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:09 Created by thunk06 on 2017-10-04 06:17:43 Original: https://sourceforge.net/p/maxima/bugs/3335/#80b5

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The expression causing the problem was generated by a previous Maxima operation It seems legal and accepted as such by factor( expr ) but not by rat( expr ) and some others

So, what do you mean by "corrected formatting" ? Have you changed anything in rat( ) that resolves the issue ? I am puzzled by the brief comment

Regards, Jacques

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:12 Created by tomasriker on 2017-10-04 06:27:09 Original: https://sourceforge.net/p/maxima/bugs/3335/#8e2d

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I corrected the formatting of your bug report. The asterisks (multiplication signs) are used for italic font if you don't use code formatting. Sorry, I can't say anything about the bug itself.

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:16 Created by thunk06 on 2017-10-04 06:50:38 Original: https://sourceforge.net/p/maxima/bugs/3335/#7d61

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I thought it was something like that but I was not sure Thanks anyway and let us hope that the bug get caught by someone Jacques

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:20 Created by tomasriker on 2017-10-05 10:29:01 Original: https://sourceforge.net/p/maxima/bugs/3335/#37f9

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Observation: When setting gcd : subres, ratsimp(expr) doesn't crash.

[rtoy]

Imported from SourceForge on 2024-07-03 02:11:23 Created by thunk06 on 2017-10-06 05:33:26 Original: https://sourceforge.net/p/maxima/bugs/3335/#7cee

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Yes, your are right However, my apllication uses rather large symbolic matrices such that the "gcd" generated through "subres" seems to have an impact on the overall speed performance "spmod " is more efficient