# Singular

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 Font size: Tiny Small Normal Large Huge Font colour [quote="lkastner"]I am trying to compute Ext for two ideals as follows: [code] ring R = 0,(x(1),x(2),x(3),x(4),x(5),x(6),x(7)),dp; ideal I = x(4)*x(6)-x(3)*x(7), x(5)^2-x(3)*x(7), x(4)*x(5)-x(2)*x(7), x(3)*x(5)-x(2)*x(6), x(1)*x(5)-x(6)*x(7), x(3)*x(4)-x(2)*x(5), x(1)*x(4)-x(5)*x(7), x(1)*x(3)-x(5)*x(6), x(1)*x(2)-x(3)*x(7), x(2)*x(5)*x(6)-x(3)^2*x(7), x(2)^2*x(6)^2-x(3)^3*x(7); qring Q = std(I); ideal D1 = x(7)^2, x(6)*x(7), x(5)*x(7), x(4)*x(7), x(1)*x(7), x(1)*x(6), x(1)^2, x(6)^3, x(5)*x(6)^2, x(4)^3; ideal D2 = x(7)^2, x(4)*x(7), x(4)^2, x(2)*x(5)*x(7), x(2)^2*x(7), x(1)^2*x(7), x(2)^2*x(4), x(2)^3*x(5), x(2)^4, x(1)^4; ideal CminD2 = x(4)^2, x(2)*x(7)^2, x(2)*x(5)*x(7), x(2)*x(4)*x(7), x(2)*x(3)*x(7), x(2)^2*x(7), x(3)*x(7)^3, x(3)^2*x(7)^2, x(3)^3*x(7), x(5)*x(6)*x(7)^3, x(2)*x(3)^2*x(6)^2, x(6)^2*x(7)^4, x(3)^4*x(6)^2; ideal CminD1 = x(6)^3, x(3)*x(6)^2*x(7), x(3)^2*x(6)^2, x(3)^2*x(6)*x(7)^2, x(3)^3*x(6)*x(7), x(3)^4*x(6), x(3)^3*x(7)^3, x(3)^4*x(7)^2, x(3)^5*x(7), x(3)^6, x(2)^2*x(3)*x(6)*x(7)^3, x(2)^2*x(3)^2*x(7)^4, x(2)^4*x(6)*x(7)^4, x(2)^4*x(3)*x(7)^5, x(2)^5*x(5)*x(7)^5, x(2)^6*x(7)^6; LIB "homolog.lib"; module M = Ext(5,syz(D1),syz(CminD2)); [/code] after quite some time this fails with the following error: [code] > module M = Ext(5,syz(D1),syz(CminD2)); ? internal error: creating matrix[7647][38235] Singular : signal 11 (v: 4020): current line:>> return(matrix(B));<< Segment fault/Bus error occurred at 7f6dd04a25a0 because of 10246 (r:1477505230) please inform the authors trying to restart... ? error occurred in or before matrix.lib::concat line 106: ` return(matrix(B));` ? wrong type declaration. type 'help matrix;' ? leaving matrix.lib::concat skipping text from `;` error at token `)` ? leaving matrix.lib::concat Auf Wiedersehen. [/code] I suspect this matrix that Singular is creating might be too big. Is this correct? If so, is there any possibility to rebuild Singular in a way such that it can handle bigger matrices?[/quote]
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Topic review - Dealing with big matrices
Author Message
 lkastner
 Post subject: Re: Dealing with big matrices
 Thank you. Unfortunately it seems that this was just covering up another bottleneck, which I (and probably you as well) already feared :Code:> module M = Ext(5,syz(D1),syz(CminD2)); Singular error: no more memorySystem 11919379k:17115977k Appl 11905349k/14029k Malloc 11880467k/0k Valloc 38912k/14029k Pages 9453/275 Regions 19:103 Internal: 9808halt 14I will try to find a smaller example. Thank you. Unfortunately it seems that this was just covering up another bottleneck, which I (and probably you as well) already feared :( :[code]> module M = Ext(5,syz(D1),syz(CminD2)); Singular error: no more memorySystem 11919379k:17115977k Appl 11905349k/14029k Malloc 11880467k/0k Valloc 38912k/14029k Pages 9453/275 Regions 19:103 Internal: 9808halt 14[/code]I will try to find a smaller example.
 Posted: Thu Nov 03, 2016 8:05 pm
 hannes
 Post subject: Re: Dealing with big matrices
 See http://www.singular.uni-kl.de:8002/trac/changeset/d7f7f499a69b3778c52e352c783b0636b840e01a/git
 Posted: Mon Oct 31, 2016 5:44 pm
 lkastner
 Post subject: Dealing with big matrices
 I am trying to compute Ext for two ideals as follows:Code:ring R = 0,(x(1),x(2),x(3),x(4),x(5),x(6),x(7)),dp;ideal I = x(4)*x(6)-x(3)*x(7),x(5)^2-x(3)*x(7),x(4)*x(5)-x(2)*x(7),x(3)*x(5)-x(2)*x(6),x(1)*x(5)-x(6)*x(7),x(3)*x(4)-x(2)*x(5),x(1)*x(4)-x(5)*x(7),x(1)*x(3)-x(5)*x(6),x(1)*x(2)-x(3)*x(7),x(2)*x(5)*x(6)-x(3)^2*x(7),x(2)^2*x(6)^2-x(3)^3*x(7);qring Q = std(I);ideal D1 = x(7)^2, x(6)*x(7), x(5)*x(7), x(4)*x(7), x(1)*x(7), x(1)*x(6), x(1)^2, x(6)^3, x(5)*x(6)^2, x(4)^3;ideal D2 = x(7)^2, x(4)*x(7), x(4)^2, x(2)*x(5)*x(7), x(2)^2*x(7), x(1)^2*x(7), x(2)^2*x(4), x(2)^3*x(5), x(2)^4, x(1)^4;ideal CminD2 = x(4)^2, x(2)*x(7)^2, x(2)*x(5)*x(7), x(2)*x(4)*x(7), x(2)*x(3)*x(7), x(2)^2*x(7), x(3)*x(7)^3, x(3)^2*x(7)^2, x(3)^3*x(7), x(5)*x(6)*x(7)^3, x(2)*x(3)^2*x(6)^2, x(6)^2*x(7)^4, x(3)^4*x(6)^2;ideal CminD1 = x(6)^3, x(3)*x(6)^2*x(7), x(3)^2*x(6)^2, x(3)^2*x(6)*x(7)^2, x(3)^3*x(6)*x(7), x(3)^4*x(6), x(3)^3*x(7)^3, x(3)^4*x(7)^2, x(3)^5*x(7), x(3)^6, x(2)^2*x(3)*x(6)*x(7)^3, x(2)^2*x(3)^2*x(7)^4, x(2)^4*x(6)*x(7)^4, x(2)^4*x(3)*x(7)^5, x(2)^5*x(5)*x(7)^5, x(2)^6*x(7)^6;LIB "homolog.lib";module M = Ext(5,syz(D1),syz(CminD2));after quite some time this fails with the following error:Code:> module M = Ext(5,syz(D1),syz(CminD2));   ? internal error: creating matrix[7647][38235]Singular : signal 11 (v: 4020):current line:>>   return(matrix(B));< module M = Ext(5,syz(D1),syz(CminD2)); ? internal error: creating matrix[7647][38235]Singular : signal 11 (v: 4020):current line:>> return(matrix(B));<
 Posted: Thu Oct 27, 2016 4:24 pm

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