Basic Matrix Question

[The Student]

Is there a difference between this matrix,

1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 0

and this matrix,

1 0 0
0 1 0
0 0 1

If not, can the first matrix be called a 4 by 4 matrix?

 

[stapel]

Is there a difference between this matrix,

1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 0

and this matrix,

1 0 0
0 1 0
0 0 1

Yes. The first is a four-by-four matrix; the second is a three-by-three matrix.

If not, can the first matrix be called a 4 by 4 matrix?

Why would the first have to be "the same" as the second in order for the first to be referred to by its dimensions? :???:

 

[The Student]

Yes. The first is a four-by-four matrix; the second is a three-by-three matrix.


Why would the first have to be "the same" as the second in order for the first to be referred to by its dimensions? :???:

I guess that it wouldn't.

Do the two matrices have the same geometrical descriptions?

 

[pka]

I guess that it wouldn't.
Do the two matrices have the same geometrical descriptions?

What do you mean by " geometrical descriptions"?

A matrix is simply a rectangular display of data points.

 

[The Student]

Okay, I get it now.