The elements of the small matrix are:

Row   Column   Value
---   ------   -----
  1        1     1.0
  1        2     2.0
  2        1     3.0
  2        2     4.0


The elements of the large matrix are:

Row   Column   Value
---   ------   -----
  1        1     1.0
  1        2     2.0
  1        3     0.0
  1        4     0.0
  2        1     3.0
  2        2     4.0
  2        3     0.0
  2        4     0.0
  3        1     0.0
  3        2     0.0
  3        3     1.0
  3        4     2.0
  4        1     0.0
  4        2     0.0
  4        3     3.0
  4        4     4.0

The elements of the extracted small matrix are:

Row   Column   Value
---   ------   -----
  1        1     0.0
  1        2     0.0
  2        1     1.0
  2        2     2.0