Data Types Data types are items that are constant throughout the life of the application and are built into the OpenMatrix language. Data Types Data types are items that are constant throughout the life of the application and are built into the OpenMatrix language. Complex The Complex data type uses imaginary literals. Double The double data type uses numeric literals. Strings The string data type involves a sequence of characters and uses string literals. Structures Structures are a data type similar to cells. However, where cells use numeric indices to refer to specific pieces of data, structures use strings. Cell Arrays Cell arrays are generic data containers. Multidimensional Matrices OML supports multidimensional matrices. Sparse Matrices Sparse matrices are a special case of 2D matrices, where only non-zero elements are stored and displayed for efficiency. A sparse matrix typically has a high percentage of zero elements.