     Next: Basic Statistical Functions Up: Selected Listing of Previous: Arithmetic and Logical

## Constructing and Modifying Compound Data and Variables

• (def var form) [Macro]

VAR is not evaluated and must be a symbol. Assigns the value of FORM to VAR and adds VAR to the list *VARIABLES* of def'ed variables. Returns VAR. If VAR is already bound and the global variable *ASK-ON-REDEFINE* is not nil then you are asked if you want to redefine the variable.

• (if-else first x y) [Function]

Takes simple or compound data items FIRST, X and Y and returns result of elementswise selecting from X if FIRST is not NIL and from Y otherwise.

• (iseq n m) [Function]

Returns a list of consecutive integers from n to m. Examples:
(iseq 3 7) returns (3 4 5 6 7)
(iseq 3 -3) returns (3 2 1 0 -1 -2 -3)

• (list &rest args) [Function]

Returns a list of its arguments

• (repeat vals times) [Function]

Repeats VALS. If TIMES is a number and VALS is a non-null, non-array atom, a list of length TIMES with all elements eq to VALS is returned. If VALS is a list and TIMES is a number then VALS is appended TIMES times. If TIMES is a list of numbers then VALS must be a list of equal length and the simpler version of repeat is mapped down the two lists. Examples:
(repeat 2 5) returns (2 2 2 2 2)
(repeat '(1 2) 3) returns (1 2 1 2 1 2)
(repeat '(4 5 6) '(1 2 3)) returns (4 5 5 6 6 6)
(repeat '((4) (5 6)) '(2 3)) returns (4 4 5 6 5 6 5 6)

• (rseq a b num) [Function]

Returns a list of NUM equally spaced points starting at A and ending at B.

• (select a &rest indices) [Function]

A can be a list or an array. If A is a list and INDICES is a single number then the appropriate element of A is returned. If is a list and INDICES is a list of numbers then the sublist of the corresponding elements is returned. If A in an array then the number of INDICES must match the ARRAY-RANK of A. If each index is a number then the appropriate array element is returned. Otherwise the INDICES must all be lists of numbers and the corresponding submatrix of A is returned. SELECT can be used in setf.

• (undef symbol) [Function]

If SYMBOL is a defined variable it is unbound and removed from the list of defined variables and returns SYMBOL.

• (vector &rest items) [Function]

Returns a vector with ITEMS as elements.

• (which x) [Function]

X is an array or a list. Returns a list of the indices where X is not NIL.     Next: Basic Statistical Functions Up: Selected Listing of Previous: Arithmetic and Logical

Luke Tierney
Tue Jan 21 15:04:48 CST 1997