In [[mathematics]], an '''incidence matrix''' is a [[Matrix (mathematics)|matrix]] that shows the relationship between two classes of objects. If the first class is ''X'' and the second is ''Y'', the matrix has one row for each element of ''X'' and one column for each element of ''Y''. The entry in row ''x'' and column ''y'' is 1 if ''x'' and ''y'' are related (called ''incident'' in this context) and 0 if they are not. There are variations; see below. | In [[mathematics]], an '''incidence matrix''' is a [[Matrix (mathematics)|matrix]] that shows the relationship between two classes of objects. If the first class is ''X'' and the second is ''Y'', the matrix has one row for each element of ''X'' and one column for each element of ''Y''. The entry in row ''x'' and column ''y'' is 1 if ''x'' and ''y'' are related (called ''incident'' in this context) and 0 if they are not. There are variations; see below. |