[Pharo-users] Matrix error

[Offray Vladimir Luna Cárdenas]

Hi,

I was testing the code here:
=[1]=========

| medMatrix   |
medMatrix := Matrix new.
medMatrix
    numberOfColumns: 7;
    numberOfRows: 5.

1 to: medMatrix numberOfRows do: [:row |
    1 to: medMatrix numberOfColumns do: [ :column |
        "medMatrix at: row at: column  put: 0."
        Transcript show: row asString, ',', column asString, '|'.
    ].
    Transcript show: cr.
].
medMatrix.

===========

and I got a transcript like this:

=[2]==========
1,1|1,2|1,3|1,4|1,5|1,6|1,7|nil2,1|2,2|2,3|2,4|2,5|2,6|2,7|nil3,1|3,2|3,3|3,4|3,5|3,6|3,7|nil4,1|4,2|4,3|4,4|4,5|4,6|4,7|nil5,1|5,2|5,3|5,4|5,5|5,6|5,7|nil'[Spotter] 
Exception while collecting processors for <Matrix>: Error: Instances of 
UndefinedObject are not indexable'
'[Spotter] Exception while collecting processors for <Matrix>: Error: 
Instances of UndefinedObject are not indexable'
'[Spotter] Exception while collecting processors for <Matrix>: Error: 
Instances of UndefinedObject are not indexable'
'[Spotter] Exception while collecting processors for <Matrix>: Error: 
Instances of UndefinedObject are not indexable'
=============

I tried also with SciSmalltalk matrix, but they seem to be only square ones.

What's is the problem with matrices? Why I'm getting Undefined Objects 
while trying to iterate or populate them?

Thanks,

Offray