[Axiom-math] Re: [Axiom-developer] Axiom: Matrix manipulations

[Waldek Hebisch]

C. Frangos wrote:
> I have tried to read in the file test.input pasted below. However, 
> I am getting continuously error messages re. the matrix Acon, and have been 
> unable to make progress.
> 

> --file test.input
> 
> --)read expandsincos.input
> 
> Acon := matrix([[1 , 0 , Lo1*sin(phi) , -sin(phi)*a , 0 , 0 , 0 , 0 , 0],_
> [0 , 1 , -Lo1*cos(phi) , a*cos(phi) , 0 , 0 , 0 , 0 , 0],_
> [1 , 0 , -Lo1*sin(phi) , 0 , -a*sin(phi), 0 , 0 , 0 , 0],-
                                                           ^
You need underscore here.
> [0 , 1 , Lo1*cos(phi) , 0 , a*cos(phi) , 0 , 0 , 0 , 0],_
> [1,0,-Lc*cos(phi)+Lo1*sin(phi),0,0,0,-a*sin(phi)*cos(delta3)_
> -a*cos(phi)*sin(delta3),0,0],_
> [0,1,-Lc*sin(phi)-Lo1*cos(phi),0,0,0,a*cos(phi)*cos(delta3)_
> -a*sin(phi)*sin(delta3),0,0],_ 
> [1,-Lc*cos(phi)-Lo1*sin(phi),0,0,(-2*sin(phi)*Lo1*sin(delta3)-sin(phi)*_
> Lc*cos(delta3)-cos(phi)*Lc*sin(delta3))*a/sqrt(4*Lo1^2*sin(delta3)^2+_
> 4*Lo1*sin(delta3)*Lc*cos(delta3)+Lc^2*cos(delta3)^2+Lc^2*sin(delta3)^2),0,0,0],_
>  

The row above has only 8 entries.

> [0,1,-Lc*sin(phi)+Lo1*cos(phi),0,0,a*(2*cos(phi)*Lo1*sin(delta3)+_
> cos(phi)*Lc*cos(delta3)-sin(phi)*Lc*sin(delta3))/sqrt(4*Lo1^2*sin(delta3)^2+_
> 4*Lo1*sin(delta3)*Lc*cos(delta3)+Lc^2*cos(delta3)^2+Lc^2*sin(delta3)^2),0,0,0],_
> [0 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , -k]])
> 
> rankAcon := rank(Acon)
> 
> nullityAcon := nullity(Acon)
> 
> Aconre := rowEchelon(Acon)
> 
> Aconnull := nullSpace(Acon)
> 
> 

After correcting the two problems above (I added leading 0 to
the short row) I get rank 8 and [[0,0,0,0,0,0,0,1,0]] as
nullSpace.


-- 
                              Waldek Hebisch
address@hidden