Matrix Diagram:

The matrix diagram shows the relationship between two, three or four groups of information. It also can give information about the relationship, such as its strength, the roles played by various individuals or measurements.
Six differently shaped matrices are possible: L, T, Y, X, C and roof-shaped, depending on how many groups must be compared.
• An L-shaped matrix relates two groups of items to each other (or one group to itself).
• A T-shaped matrix relates three groups of items: groups B and C are each related to A. Groups B and C are not related to each other.
• A Y-shaped matrix relates three groups of items. Each group is related to the other two in a circular fashion.
• A C-shaped matrix relates three groups of items all together simultaneously, in 3-D.
• An X-shaped matrix relates four groups of items. Each group is related to two others in a circular fashion.
• A roof-shaped matrix relates one group of items to itself. It is usually used along with an L- or T-shaped matrix.
L-shaped 2 groups A B (or A A)

T-shaped 3 groups B A C but not B C

Y-shaped 3 groups A B C A

C-shaped 3 groups All three simultaneously (3-D)
X-shaped 4 groups A B C D A but not A C or B D

Roof-shaped 1 group A A when also A B in L or T