# Mat Grouping

MAT grouping is now allowed in all full screen-processing statements. This feature allows you to indicate that input or output should alternate between all MAT variables that are specified within parentheses in the I/O list.

In the following code fragment, the A$ variable identifies the positions on the screen from which input values should be drawn. As usual, Business Rules will assign the first input value to the first element of B$. However, because the B$ and C matrices are specified within parentheses, it will then assign the second input value to the first element of C. The third value will go to B$, the fourth to C, and so on until both matrices are fully assigned. The last input value will go to X$.

00020 INPUT FIELDS A$: (MAT B$,MAT C),X$

Without MAT grouping, the above line must be coded as follows in order to achieve the same results (this example assumes that B$ and C have each been dimensioned for five elements):

00020 INPUT FIELDS A$: B$(1),C(1),B$(2),C(2),B$(3),C(3),B$(4),C(4),B$(5),C(5),X$

MAT grouping is a lot easier to code, it executes faster, and most importantly it handles much larger arrays than are possible without using MAT grouping, as the resulting compiled line takes up less space in memory. The number of matrices that can be grouped together is 62, which in practical terms are no limit. All matrices in a group must have the same number of elements per matrix, or an error 0106 will result. Only MAT variables may be used in such groupings.

See error 0106 for additional information.