Matrix as Visual Point

A visual point P having the coordinates (a,b) is represented like this, P=(a,b), in GeoGebra.

A matrix is represented by a list. The matrix

is represented by a list having two elements (the two rows), each element is represented by another list having three elements. The matrix A is hence represented by the list A={{1,2,3},{4,5,6}}.

You can get element number n in a list l by using the command : Element[l,n]

You can not visualize a matrix. If you want the matrix

to show up on the drawing pad as a point P, you do like this:

P=(Element[Element[v,1],1],Element[Element[v,2],1])

Since we are going to represent eight matrices as points, it is convenient to make a tool transforming a 2×1-matrix to a point.

Make a tool

• Input a matrix v={{2},{5}}
• Input a point P:
  P=(Element[Element[v,1],1],Element[Element[v,2],1])
  P should appear in the drawing pad.
• Choose Create New Tool under the menu Tools
• Pick Point P as Output Objects and click Next
• Pick List v as Input Objects and click Next
• Input a tool name like ”From matrix to point” and click Finish.

Now there is a new tool in the tool bar. Delete the point P. Try clicking on the new tool and then on the list v in the algebra view. A new point A should show up. Delete both v and A.