how can i multiply 2 matrices with different dimension ?

i have Rr=3*3 matrices and PQRg=3*110 and i want to multiply them and get AnVel=[Rr]*[PQRg]which is 3*110 ? how is possible?

3 Comments

Rr * PQRg
would be 3 x 110 under those circumstances, so it is not clear what your question is?
actually i want to do it in alopp and its not work :( thats the problem ,i know the law and its works outside of the loop :(
for i=1:111
xx=XG(:,i)/norm(XG(:,i));
yy=YG(:,i)/norm(YG(:,i));
zz= ZG(:,i)/norm(ZG(:,i));
Rr=[xx,yy,zz];
determinante=det(Rr);
time=[1:1:111]';
Time=time/120;
[R1 R2 R3]=dcm2angle (Rr); %[yaw, pitch, roll] = dcm2angle( dcm )
TableTeta(i,:)=[R2];
TableFi(i,:)=[R1];
TableAlfa(i,:)=[R3];
deFi= diff(TableFi);
deAlfa= diff(TableAlfa);
deTeta=diff(TableTeta);
%VELOCITà ANGOLARE
Pg=(deAlfa*sin(TableFi(i,:))*sin(TableTeta(i,:))+deFi*cos(TableTeta(i,:))).*120;
Qg=(deAlfa*sin(TableFi(i,:))*cos(TableTeta(i,:))-deFi*sin(TableTeta(i,:))).*120;
Rg=(deAlfa*cos(TableFi(i,:))+deTeta).*120;
PG=Pg';
QG=Qg';
RG=Rg';
PQRg=[PG; QG; RG]
AnVel1=Rr*PQRg;
AnVel=[AnVel1]';
end
You are overwriting all of AnVel every iteration of the "for" loop. It seems unlikely that is what you want to do.

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Answers (2)

Um, read the getting started tutorials?
AnVel = Rr*PQRg;
It is legal to read the documentation. You might even learn how to use the language.

1 Comment

sorry but this is not working inside a loop which i send you the loop now ??
for i=1:111
xx=XG(:,i)/norm(XG(:,i));
yy=YG(:,i)/norm(YG(:,i));
zz= ZG(:,i)/norm(ZG(:,i));
Rr=[xx,yy,zz];
determinante=det(Rr);
time=[1:1:111]';
Time=time/120;
[R1 R2 R3]=dcm2angle (Rr); %[yaw, pitch, roll] = dcm2angle( dcm )
TableTeta(i,:)=[R2];
TableFi(i,:)=[R1];
TableAlfa(i,:)=[R3];
deFi= diff(TableFi);
deAlfa= diff(TableAlfa);
deTeta=diff(TableTeta);
%VELOCITà ANGOLARE
Pg=(deAlfa*sin(TableFi(i,:))*sin(TableTeta(i,:))+deFi*cos(TableTeta(i,:))).*120;
Qg=(deAlfa*sin(TableFi(i,:))*cos(TableTeta(i,:))-deFi*sin(TableTeta(i,:))).*120;
Rg=(deAlfa*cos(TableFi(i,:))+deTeta).*120;
PG=Pg';
QG=Qg';
RG=Rg';
PQRg=[PG; QG; RG]
AnVel1=Rr*PQRg;
AnVel=[AnVel1]';
end

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YOu can happily multiply them using *.
Rr = rand(3,3) ;
PQRg = rand(3,110) ;
P = Rr*PQRg
Remmember multiplication law?

Asked:

on 25 Oct 2017

Commented:

on 26 Oct 2017

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