Matrices and Arrays

XLISP-STAT includes support for multidimensional arrays patterned after the Common Lisp standard described in detail in Steele [12]. The functions supported are listed in Section [*] of the appendix.

In addition to the standard Common Lisp array functions XLISP-STAT also includes a number of linear algebra functions such as "2D inverse, "2D solve and "2D transpose. These functions are listed in the appendix as well.

At present XLISP-STAT does not provide any facility for nice printing of matrices and other arrays. An array is printed using the standard Common Lisp format. For example, a 2 by 3 matrix with rows (1 2 3) and (4 5 6) is printed as

#2A((1 2 3)(4 5 6))
The "2D select function can be used to extract elements or subarrays from an array. If "2D A is a two dimensional array then the expression
(select a 0 1)
will return the element 1 of the row 0 of "2D A. The expression
(select a (list 0 1) (list 0 1))
returns the upper left hand corner of "2D A.