N-dimensional Array Objects (NAOs)

slot number

Index of entry in internal table used to provide fast access to NAOs.

sequence number

Number (starting from 1) assigned in order of creation of NAOs.

OOC-name

Name of object-oriented command associated with NAO. Also used as unique identifier of NAO.

reference count

Number of Tcl variables, NAOs, windows, etc. pointing to this NAO. If the count decrements to 0 then NAP deletes the NAO and its associated OOC.

nap_cd

pointer to NAP structure created for each interpreter.

dataType

one of the following:

Name	Description
c8	8-bit character
i8	8-bit signed integer
i16	16-bit signed integer
i32	32-bit signed integer
u8	8-bit unsigned integer
u16	16-bit unsigned integer
u32	32-bit unsigned integer
f32	32-bit floating-point
f64	64-bit floating-point
ragged	compressed
boxed	slot numbers (used as pointers to NAOs)

step

An efficiency hint for searching vectors. If this component is undefined before a search then NAP defines it according to whether the vector is

• unordered
• sorted into ascending order
• sorted into descending order
• quasi-arithmetic-progression i.e. a vector all of whose steps are equal, except possibly the final one which may be shorter.

mortal

This is set FALSE for NAOs (e.g. standard missing values) which must not be deleted regardless of reference count.

format

Text containing C format for printing.

label

Text containing title, description of data, etc.

unit

Text defining unit of measure.

rank

number of dimensions.

nels

number of elements = product(shape).

nbytes

number of bytes in NAO. Mainly for debugging.

link slot

slot number (0 = none) of link NAO, which can be used to attach further information to a NAO (possibly via a boxed NAO which could link to any number of further NAOs).

next slot

used internally to create NAO death list when executing a Tcl procedure defining a NAP function. (0 = none)

missing value slot

slot number (0=none) of missing-value NAO.

pointer to missing value

pointer to missing value NAO (for fast access).

pointer to missing value function

This function tests whether an element of a NAO is missing.

ragged start slot number

slot number (0=none) of vector NAO giving start index of each row of ragged array.

shape

sizes of dimensions.

dimension names

names (if any) of dimensions.

coordinate-variable slot numbers

slot numbers (0 = none) of CVs.

data

Main data.

Author: Harvey Davies       © 2002, CSIRO Australia.       Legal Notice and Disclaimer CVS Version Details: $Id: nao.html,v 1.3 2005/02/02 00:41:44 dav480 Exp $