Re: [Scilab-users] number od decimals with csvWrite
The simplest way is to use round A=rand(3,3); B=round(100*A)/100; Serge Steer Le 25/06/2015 22:07, Simone Meroni a écrit : Hi I want to write some data and export them with csvWrite I need to have no more than 2 decimals for aesthetic reasons. How can I set the number of decimals? Thanks, Simone Meroni ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] eigs calculation
Hi Paul, I don't really like a function that gives different answers for the very same input. That sounds like a bug to me. That being said, from the data you showed, it is not clear that your eigenvector are really different. If what you show is just a difference in the norm of the difference between the eigenvalue at iteration 1 and N, that might be OK. Indeed, if v is an eigenvector, a.v with a non zero-scalar, is also an eigenvector. You should check whether v1 and vN are colinear: if they are, the results are not really different, they just differ by a scaling factor. But I would still call it a bug, as a function should always give the same answer when given the same input parameters. Cheers, Antoine Le Jeudi 25 Juin 2015 17:17 CEST, "Carrico, Paul" a écrit: > Dear all > > I'm still working on my "eigs" issue topic and I'm still trying to understand > what's going wrong; > > I run a test case : > - same function is launched 10 times > - each time the input data are recorded (K,M) > - for each loop the eigenvalues u and the eigenvectors v are recorded > > Then the values of each loop are compared with the values of the loop 1 > > If K,M,u remains strictly identical, it is not the case for u (the > eigenvectors) ... why ? > > I've ever check any initialization issue, but everything seems to be ok > > Paul > > PS : the results of this case > > Max delta v2 - v1 = 453.857 > Max delta K2 - K1 = 0 > Max delta M2 - M1 = 0 > > Max delta v3 - v1 = 549.214 > Max delta K3 - K1 = 0 > Max delta M3 - M1 = 0 > > Max delta v4 - v1 = 585.95 > Max delta K4 - K1 = 0 > Max delta M4 - M1 = 0 > > Max delta v5 - v1 = 379.702 > Max delta K5 - K1 = 0 > Max delta M5 - M1 = 0 > > Max delta v6 - v1 = 489.844 > Max delta K6 - K1 = 0 > Max delta M6 - M1 = 0 > > Max delta v7 - v1 = 439.221 > Max delta K7 - K1 = 0 > Max delta M7 - M1 = 0 > > Max delta v8 - v1 = 432.406 > Max delta K8 - K1 = 0 > Max delta M8 - M1 = 0 > > Max delta v9 - v1 = 351.752 > Max delta K9 - K1 = 0 > Max delta M9 - M1 = 0 > > Max delta v10 - v1 = 554.515 > Max delta K10 - K1 = 0 > Max delta M10 - M1 = 0 > > -Message d'origine- > De : Carrico, Paul > Envoyé : mercredi 17 juin 2015 22:18 > À : International users mailing list for Scilab. > Objet : RE: [Scilab-users] eigs calculation > > Dear All > > Thanks for the answers. > > To give more information's on what I'm doing (That's quite new I confess), > I'm performing a (basic) finite element calculation with beams using sparse > matrix (stiffness matrix K and mass matrix M). > [u,v] = > eigs(K((ddl_elem+1):$,(ddl_elem+1):$),M((ddl_elem+1):$,(ddl_elem+1):$),n,"SM"); > > Nota: ddl means dof > > I'm calculated first the natural frequencies using (K - omega^2.M).x=0 ... > the pulse (or circular frequencies) are no more and no less than the > eigenvalues of the above system (u = omega^2). > > Just a "mechanical" remark: since the beam is clamped in one side (and free > on the tip), it is absolutely normal that you find twice the same natural > frequency (1rst mode in one direction, the second one in a new direction at > 90°) I've been really surprised to find it, but happy at the same time > ... > > The origin of my question was: since it obvious that the results are strongly > sensitive to the "units" (i.e. the numbers), I'm wondering if there is a way > to control the accuracy of the eigenvalues calculation using eigs keywords > ... > > In any way, thanks for the debate > > Paul > > EXPORT CONTROL : > Cet email ne contient pas de données techniques > This email does not contain technical data > ___ > users mailing list > users@lists.scilab.org > http://lists.scilab.org/mailman/listinfo/users > ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] eigs calculation
Hi Antoine,
Thanks for the comments; In attachment the results of the calculations (note
that the modal effective depends on the eigenvectors)
The calculation for the difference calculations are described herebellow ..
Paul
###"
// prog principal
nbre = 10;
for k = 1 : nbre
printf("\n***\nIteration num %d\n",k);
s1 = " ...
[u" + string(k) + ",v" + string(k) + ",K" + string(k) + ",M" + string(k) +
"] = calcul_v() , ...
[nl,nc] = size(v" + string(k) + ") , ...
save(''u" + string(k) + ".bin'',''u" + string(k) + "'') , ...
save(''v" + string(k) + ".bin'',''v" + string(k) + "'') , ...
clear nl , ...
clear nc , ...
save(''K" + string(k) + ".bin'',''K" + string(k) + "'') , ...
save(''M" + string(k) + ".bin'',''M" + string(k) + "'') , ...
";
execstr(s1) ;
end
printf("\n\n");
// difference v1 - v2
for k = 2 : nbre
s2 = " ...
printf(""(eigenvalues) Max delta u%d - u1 = %g\n"",k,abs(max(u" + string(k)
+ " - u1))) , ...
printf(""(eigenvectors) Max delta v%d - v1 = %g\n"",k,abs(max(v" +
string(k) + " - v1))) , ...
printf(""(input matrix) Max delta K%d - K1 = %g\n"",k,abs(max(K" +
string(k) + " - K1))) , ...
printf(""(input matrix) Max delta M%d - M1 = %g\n"",k,abs(max(M" +
string(k) + " - M1))) , ...
";
execstr(s2) ;
printf("\n");
end
##"
-Message d'origine-
De : users [mailto:users-boun...@lists.scilab.org] De la part de Antoine
Monmayrant Envoyé : vendredi 26 juin 2015 10:50 À : International users mailing
list for Scilab.
Objet : Re: [Scilab-users] eigs calculation
Hi Paul,
I don't really like a function that gives different answers for the very same
input.
That sounds like a bug to me.
That being said, from the data you showed, it is not clear that your
eigenvector are really different.
If what you show is just a difference in the norm of the difference between the
eigenvalue at iteration 1 and N, that might be OK.
Indeed, if v is an eigenvector, a.v with a non zero-scalar, is also an
eigenvector.
You should check whether v1 and vN are colinear: if they are, the results are
not really different, they just differ by a scaling factor.
But I would still call it a bug, as a function should always give the same
answer when given the same input parameters.
Cheers,
Antoine
Le Jeudi 25 Juin 2015 17:17 CEST, "Carrico, Paul"
a écrit:
> Dear all
>
> I'm still working on my "eigs" issue topic and I'm still trying to
> understand what's going wrong;
>
> I run a test case :
> - same function is launched 10 times
> - each time the input data are recorded (K,M)
> - for each loop the eigenvalues u and the eigenvectors v are recorded
>
> Then the values of each loop are compared with the values of the loop
> 1
>
> If K,M,u remains strictly identical, it is not the case for u (the
> eigenvectors) ... why ?
>
> I've ever check any initialization issue, but everything seems to be
> ok
>
> Paul
>
> PS : the results of this case
>
> Max delta v2 - v1 = 453.857
> Max delta K2 - K1 = 0
> Max delta M2 - M1 = 0
>
> Max delta v3 - v1 = 549.214
> Max delta K3 - K1 = 0
> Max delta M3 - M1 = 0
>
> Max delta v4 - v1 = 585.95
> Max delta K4 - K1 = 0
> Max delta M4 - M1 = 0
>
> Max delta v5 - v1 = 379.702
> Max delta K5 - K1 = 0
> Max delta M5 - M1 = 0
>
> Max delta v6 - v1 = 489.844
> Max delta K6 - K1 = 0
> Max delta M6 - M1 = 0
>
> Max delta v7 - v1 = 439.221
> Max delta K7 - K1 = 0
> Max delta M7 - M1 = 0
>
> Max delta v8 - v1 = 432.406
> Max delta K8 - K1 = 0
> Max delta M8 - M1 = 0
>
> Max delta v9 - v1 = 351.752
> Max delta K9 - K1 = 0
> Max delta M9 - M1 = 0
>
> Max delta v10 - v1 = 554.515
> Max delta K10 - K1 = 0
> Max delta M10 - M1 = 0
>
> -Message d'origine-
> De : Carrico, Paul
> Envoyé : mercredi 17 juin 2015 22:18
> À : International users mailing list for Scilab.
> Objet : RE: [Scilab-users] eigs calculation
>
> Dear All
>
> Thanks for the answers.
>
> To give more information's on what I'm doing (That's quite new I confess),
> I'm performing a (basic) finite element calculation with beams using sparse
> matrix (stiffness matrix K and mass matrix M).
> [u,v] =
> eigs(K((ddl_elem+1):$,(ddl_elem+1):$),M((ddl_elem+1):$,(ddl_elem+1):$)
> ,n,"SM");
>
> Nota: ddl means dof
>
> I'm calculated first the natural frequencies using (K - omega^2.M).x=0 ...
> the pulse (or circular frequencies) are no more and no less than the
> eigenvalues of the above system (u = omega^2).
>
> Just a "mechanical" remark: since the beam is clamped in one side (and free
> on the tip), it is absolutely normal that you find twice the same natural
> frequency (1rst mode in one direction, the second one in a new direction at
> 90°) I've been really surprised to find it, but happy at the same time
> ...
>
> The
Re: [Scilab-users] eigs calculation
Le Vendredi 26 Juin 2015 11:16 CEST, "Carrico, Paul"
a écrit:
> Hi Antoine,
>
> Thanks for the comments; In attachment the results of the calculations (note
> that the modal effective depends on the eigenvectors)
>
> The calculation for the difference calculations are described herebellow ..
I'm confused, who's who:
u = value or vector
v = value or vector ?
Antoine
>
>
> Paul
>
> ###"
> // prog principal
> nbre = 10;
> for k = 1 : nbre
> printf("\n***\nIteration num %d\n",k);
> s1 = " ...
> [u" + string(k) + ",v" + string(k) + ",K" + string(k) + ",M" + string(k)
> + "] = calcul_v() , ...
> [nl,nc] = size(v" + string(k) + ") , ...
> save(''u" + string(k) + ".bin'',''u" + string(k) + "'') , ...
> save(''v" + string(k) + ".bin'',''v" + string(k) + "'') , ...
> clear nl , ...
> clear nc , ...
> save(''K" + string(k) + ".bin'',''K" + string(k) + "'') , ...
> save(''M" + string(k) + ".bin'',''M" + string(k) + "'') , ...
> ";
> execstr(s1) ;
>
> end
>
> printf("\n\n");
>
> // difference v1 - v2
> for k = 2 : nbre
> s2 = " ...
> printf(""(eigenvalues) Max delta u%d - u1 = %g\n"",k,abs(max(u" +
> string(k) + " - u1))) , ...
> printf(""(eigenvectors) Max delta v%d - v1 = %g\n"",k,abs(max(v" +
> string(k) + " - v1))) , ...
> printf(""(input matrix) Max delta K%d - K1 = %g\n"",k,abs(max(K" +
> string(k) + " - K1))) , ...
> printf(""(input matrix) Max delta M%d - M1 = %g\n"",k,abs(max(M" +
> string(k) + " - M1))) , ...
> ";
> execstr(s2) ;
> printf("\n");
> end
> ##"
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> -Message d'origine-
> De : users [mailto:users-boun...@lists.scilab.org] De la part de Antoine
> Monmayrant Envoyé : vendredi 26 juin 2015 10:50 À : International users
> mailing list for Scilab.
> Objet : Re: [Scilab-users] eigs calculation
>
> Hi Paul,
>
> I don't really like a function that gives different answers for the very same
> input.
> That sounds like a bug to me.
> That being said, from the data you showed, it is not clear that your
> eigenvector are really different.
> If what you show is just a difference in the norm of the difference between
> the eigenvalue at iteration 1 and N, that might be OK.
> Indeed, if v is an eigenvector, a.v with a non zero-scalar, is also an
> eigenvector.
> You should check whether v1 and vN are colinear: if they are, the results are
> not really different, they just differ by a scaling factor.
> But I would still call it a bug, as a function should always give the same
> answer when given the same input parameters.
>
> Cheers,
>
> Antoine
>
>
> Le Jeudi 25 Juin 2015 17:17 CEST, "Carrico, Paul"
> a écrit:
>
> > Dear all
> >
> > I'm still working on my "eigs" issue topic and I'm still trying to
> > understand what's going wrong;
> >
> > I run a test case :
> > - same function is launched 10 times
> > - each time the input data are recorded (K,M)
> > - for each loop the eigenvalues u and the eigenvectors v are recorded
> >
> > Then the values of each loop are compared with the values of the loop
> > 1
> >
> > If K,M,u remains strictly identical, it is not the case for u (the
> > eigenvectors) ... why ?
> >
> > I've ever check any initialization issue, but everything seems to be
> > ok
> >
> > Paul
> >
> > PS : the results of this case
> >
> > Max delta v2 - v1 = 453.857
> > Max delta K2 - K1 = 0
> > Max delta M2 - M1 = 0
> >
> > Max delta v3 - v1 = 549.214
> > Max delta K3 - K1 = 0
> > Max delta M3 - M1 = 0
> >
> > Max delta v4 - v1 = 585.95
> > Max delta K4 - K1 = 0
> > Max delta M4 - M1 = 0
> >
> > Max delta v5 - v1 = 379.702
> > Max delta K5 - K1 = 0
> > Max delta M5 - M1 = 0
> >
> > Max delta v6 - v1 = 489.844
> > Max delta K6 - K1 = 0
> > Max delta M6 - M1 = 0
> >
> > Max delta v7 - v1 = 439.221
> > Max delta K7 - K1 = 0
> > Max delta M7 - M1 = 0
> >
> > Max delta v8 - v1 = 432.406
> > Max delta K8 - K1 = 0
> > Max delta M8 - M1 = 0
> >
> > Max delta v9 - v1 = 351.752
> > Max delta K9 - K1 = 0
> > Max delta M9 - M1 = 0
> >
> > Max delta v10 - v1 = 554.515
> > Max delta K10 - K1 = 0
> > Max delta M10 - M1 = 0
> >
> > -Message d'origine-
> > De : Carrico, Paul
> > Envoyé : mercredi 17 juin 2015 22:18
> > À : International users mailing list for Scilab.
> > Objet : RE: [Scilab-users] eigs calculation
> >
> > Dear All
> >
> > Thanks for the answers.
> >
> > To give more information's on what I'm doing (That's quite new I confess),
> > I'm performing a (basic) finite element calculation with beams using
> > sparse matrix (stiffness matrix K and mass matrix M).
> > [u,v] =
> > eigs(K((ddl_elem+1):$,(ddl_elem+1):$),M((ddl_elem+1):$,(ddl_elem+1):$)
> > ,n,"SM");
> >
> > Nota: ddl means dof
> >
> > I'm calculated first the natural
Re: [Scilab-users] eigs calculation
U = eigenvalues -> matrix (nx1)
V = eigenvectors -> matrix (nxn)
NB: n = 12 since I'm foccusing of the n first natural frequencies
Paul
-Message d'origine-
De : users [mailto:users-boun...@lists.scilab.org] De la part de Antoine
Monmayrant Envoyé : vendredi 26 juin 2015 12:26 À : International users mailing
list for Scilab.
Objet : Re: [Scilab-users] eigs calculation
Le Vendredi 26 Juin 2015 11:16 CEST, "Carrico, Paul"
a écrit:
> Hi Antoine,
>
> Thanks for the comments; In attachment the results of the calculations
> (note that the modal effective depends on the eigenvectors)
>
> The calculation for the difference calculations are described herebellow ..
I'm confused, who's who:
u = value or vector
v = value or vector ?
Antoine
>
>
> Paul
>
> ###"
> // prog principal
> nbre = 10;
> for k = 1 : nbre
> printf("\n***\nIteration num %d\n",k);
> s1 = " ...
> [u" + string(k) + ",v" + string(k) + ",K" + string(k) + ",M" + string(k)
> + "] = calcul_v() , ...
> [nl,nc] = size(v" + string(k) + ") , ...
> save(''u" + string(k) + ".bin'',''u" + string(k) + "'') , ...
> save(''v" + string(k) + ".bin'',''v" + string(k) + "'') , ...
> clear nl , ...
> clear nc , ...
> save(''K" + string(k) + ".bin'',''K" + string(k) + "'') , ...
> save(''M" + string(k) + ".bin'',''M" + string(k) + "'') , ...
> ";
> execstr(s1) ;
>
> end
>
> printf("\n\n");
>
> // difference v1 - v2
> for k = 2 : nbre
> s2 = " ...
> printf(""(eigenvalues) Max delta u%d - u1 = %g\n"",k,abs(max(u" +
> string(k) + " - u1))) , ...
> printf(""(eigenvectors) Max delta v%d - v1 = %g\n"",k,abs(max(v" +
> string(k) + " - v1))) , ...
> printf(""(input matrix) Max delta K%d - K1 = %g\n"",k,abs(max(K" +
> string(k) + " - K1))) , ...
> printf(""(input matrix) Max delta M%d - M1 = %g\n"",k,abs(max(M" +
> string(k) + " - M1))) , ...
> ";
> execstr(s2) ;
> printf("\n");
> end
> ##"
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> -Message d'origine-
> De : users [mailto:users-boun...@lists.scilab.org] De la part de Antoine
> Monmayrant Envoyé : vendredi 26 juin 2015 10:50 À : International users
> mailing list for Scilab.
> Objet : Re: [Scilab-users] eigs calculation
>
> Hi Paul,
>
> I don't really like a function that gives different answers for the very same
> input.
> That sounds like a bug to me.
> That being said, from the data you showed, it is not clear that your
> eigenvector are really different.
> If what you show is just a difference in the norm of the difference between
> the eigenvalue at iteration 1 and N, that might be OK.
> Indeed, if v is an eigenvector, a.v with a non zero-scalar, is also an
> eigenvector.
> You should check whether v1 and vN are colinear: if they are, the results are
> not really different, they just differ by a scaling factor.
> But I would still call it a bug, as a function should always give the same
> answer when given the same input parameters.
>
> Cheers,
>
> Antoine
>
>
> Le Jeudi 25 Juin 2015 17:17 CEST, "Carrico, Paul"
> a écrit:
>
> > Dear all
> >
> > I'm still working on my "eigs" issue topic and I'm still trying to
> > understand what's going wrong;
> >
> > I run a test case :
> > - same function is launched 10 times
> > - each time the input data are recorded (K,M)
> > - for each loop the eigenvalues u and the eigenvectors v are
> > recorded
> >
> > Then the values of each loop are compared with the values of the
> > loop
> > 1
> >
> > If K,M,u remains strictly identical, it is not the case for u (the
> > eigenvectors) ... why ?
> >
> > I've ever check any initialization issue, but everything seems to be
> > ok
> >
> > Paul
> >
> > PS : the results of this case
> >
> > Max delta v2 - v1 = 453.857
> > Max delta K2 - K1 = 0
> > Max delta M2 - M1 = 0
> >
> > Max delta v3 - v1 = 549.214
> > Max delta K3 - K1 = 0
> > Max delta M3 - M1 = 0
> >
> > Max delta v4 - v1 = 585.95
> > Max delta K4 - K1 = 0
> > Max delta M4 - M1 = 0
> >
> > Max delta v5 - v1 = 379.702
> > Max delta K5 - K1 = 0
> > Max delta M5 - M1 = 0
> >
> > Max delta v6 - v1 = 489.844
> > Max delta K6 - K1 = 0
> > Max delta M6 - M1 = 0
> >
> > Max delta v7 - v1 = 439.221
> > Max delta K7 - K1 = 0
> > Max delta M7 - M1 = 0
> >
> > Max delta v8 - v1 = 432.406
> > Max delta K8 - K1 = 0
> > Max delta M8 - M1 = 0
> >
> > Max delta v9 - v1 = 351.752
> > Max delta K9 - K1 = 0
> > Max delta M9 - M1 = 0
> >
> > Max delta v10 - v1 = 554.515
> > Max delta K10 - K1 = 0
> > Max delta M10 - M1 = 0
> >
> > -Message d'origine-
> > De : Carrico, Paul
> > Envoyé : mercredi 17 juin 2015 22:18 À : International users mailing
> > list for Scilab.
> > Objet : RE: [Scilab-users] eigs calculation
> >
> > Dear All
> >
> > Thanks for the
Re: [Scilab-users] number od decimals with csvWrite
Hi. I suppose no need to use the round function. Use csvWrite: A=rand(3,3); csvWrite(A, 'file_with_A_data.txt', ' ', '.', "%.2e") 7.26e-01 2.32e-01 8.83e-01 1.99e-01 2.31e-01 6.53e-01 5.44e-01 2.16e-01 3.08e-01 By the way, if you want to use a comma as a decimal mark the fourth parameter should be ',': csvWrite(A, 'file_with_A_data.txt', ' ', ',', "%.2e") Stanislav 26.06.2015 12:09, Serge Steer пишет: The simplest way is to use round A=rand(3,3); B=round(100*A)/100; Serge Steer Le 25/06/2015 22:07, Simone Meroni a écrit : Hi I want to write some data and export them with csvWrite I need to have no more than 2 decimals for aesthetic reasons. How can I set the number of decimals? Thanks, Simone Meroni ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
