Hello,

I am new to sMath. During my first steps on playing around with matrices and summation of matrices I found the following bug:

[LIVE width=368 height=456]http://smath.info/live/?file=2284[/LIVE]

Hello,

I agree, it is a bit unusual. Perhaps it is the result of Andrey's efforts regarding the introduction of block (nested) matrices.
[MATH=eng]I←mat(1,0,0,0,1,0,0,0,1,3,3)[/MATH][MATH=eng]C←mat(0,0,1,3,1)[/MATH]
[MATH=eng]sum((I*C),i,1,2)=mat(0,0,2,3,1)[/MATH]
[MATH=eng]sum((I*mat(0,0,1,3,1)),i,1,2)=mat(0,0,mat(2,0,0,0,2,0,0,0,2,3,3),3,1)[/MATH]
[MATH=eng]sum((mat(1,0,0,0,1,0,0,0,1,3,3)*C),i,1,2)=mat(mat(0,0,2,3,1),0,0,0,mat(0,0,2,3,1),0,0,0,mat(0,0,2,3,1),3,3)[/MATH]

Regards,
Radovan

Hello Radovan,

thank you for your quick reply! It sounds very interesting, these block (nested) matrices.
How do I have to interpret the results?

[LIVE width=534 height=449]http://smath.info/live/?file=2286[/LIVE]

Hello,

In my opinion, this should be interpreted as a bug - as you mentioned in the first place. Until Andrey gives the final answer, we should be aware of this behavior that you've find out.

Regards,
Radovan

Hello,

Here is more about block matrices:
[MATH=eng]A←mat(1,0,0,0,1,0,0,0,1,3,3)[/MATH][MATH=eng]B←mat(0,0,1,3,1)[/MATH]
[MATH=eng]mat(A,A,A,A,2,2)*mat(B,B,2,1)=mat(mat(0,0,2,3,1),mat(0,0,2,3,1),2,1)[/MATH][MATH=eng]mat(A,A,A,A,2,2)*mat(0,1,2,1)=mat(mat(1,0,0,0,1,0,0,0,1,3,3),mat(1,0,0,0,1,0,0,0,1,3,3),2,1)[/MATH]
[MATH=eng]sum((mat(A,A,A,A,2,2)*mat(B,B,2,1)),i,1,2)=mat(mat(0,0,4,3,1),mat(0,0,4,3,1),2,1)[/MATH][MATH=eng]sum((mat(A,A,A,A,2,2)*mat(0,1,2,1)),i,1,2)=mat(mat(2,0,0,0,2,0,0,0,2,3,3),mat(2,0,0,0,2,0,0,0,2,3,3),2,1)[/MATH]
[MATH=eng]sum((A*mat(0,1,2,1)),i,1,2)=mat(0,mat(2,0,0,0,2,0,0,0,2,3,3),2,1)[/MATH]
but this, of course, is not allowed:
[MATH=eng]A*mat(0,1,2,1)=#[/MATH]

I think that Andrey did not finish all the issues regarding block matrices yet.

Regards,
Radovan