Numeric - Grid Variable Set

A numeric - grid is a generalization of a numeric - multi variable set, where the variables can be thought of as ordered in two dimensions. This variable set structure occurs most commonly in survey data, where a series of related numeric questions are asked in a loop, or, a grid-style question is presented. For example:

Q2a. How many times did you drink these brands 'at home' in the past week?

___ Coca-Cola
___ Diet Coke
___ Coke Zero
___ Pepsi
___ Diet Pepsi
___ Pepsi Max

Q2a. How many times did you drink these brands 'out and about' in the past week?

___ Coca-Cola
___ Diet Coke
___ Coke Zero
___ Pepsi
___ Diet Pepsi
___ Pepsi Max