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  • Committer: Bazaar Package Importer
  • Author(s): Alexandre Fayolle
  • Date: 2006-06-28 10:45:03 UTC
  • mfrom: (1.2.1 upstream)
  • mto: This revision was merged to the branch mainline in revision 5.
  • Revision ID: james.westby@ubuntu.com-20060628104503-cc251q5o5j3e2k10
  * Fixed call to pyversions in debian/rules which failed on recent versions 
    of pyversions
  * Fixed clean rule in debian/rules which left the stamp files behind
  * Acknowledge NMU
  * Added Alexandre Fayolle to uploaders

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doc/html/x3623.html
 
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
 
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<HTML
 
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><HEAD
 
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><TITLE
 
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>The Description class</TITLE
 
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><META
 
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NAME="GENERATOR"
 
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CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
 
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REL="HOME"
 
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TITLE="PyTables User's Guide"
 
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HREF="index.html"><LINK
 
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REL="UP"
 
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TITLE="Library Reference"
 
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HREF="c1381.html"><LINK
 
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REL="PREVIOUS"
 
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TITLE="The Cols class"
 
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HREF="x3528.html"><LINK
 
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REL="NEXT"
 
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TITLE="The Column class"
 
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HREF="x3737.html"></HEAD
 
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><BODY
 
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CLASS="sect1"
 
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BGCOLOR="#FFFFFF"
 
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TEXT="#000000"
 
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LINK="#0000FF"
 
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VLINK="#840084"
 
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ALINK="#0000FF"
 
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><DIV
 
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CLASS="NAVHEADER"
 
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><TABLE
 
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SUMMARY="Header navigation table"
 
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WIDTH="100%"
 
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BORDER="0"
 
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CELLPADDING="0"
 
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CELLSPACING="0"
 
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><TR
 
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><TH
 
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COLSPAN="3"
 
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ALIGN="center"
 
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><SPAN
 
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CLASS="markup"
 
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>PyTables</SPAN
 
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> User's Guide: Hierarchical datasets in Python - Release 1.3.2</TH
 
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></TR
 
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><TR
 
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><TD
 
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WIDTH="10%"
 
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ALIGN="left"
 
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VALIGN="bottom"
 
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><A
 
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HREF="x3528.html"
 
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ACCESSKEY="P"
 
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>Prev</A
 
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></TD
 
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><TD
 
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WIDTH="80%"
 
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ALIGN="center"
 
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VALIGN="bottom"
 
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>Chapter 4. Library Reference</TD
 
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><TD
 
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WIDTH="10%"
 
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ALIGN="right"
 
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VALIGN="bottom"
 
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><A
 
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HREF="x3737.html"
 
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ACCESSKEY="N"
 
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>Next</A
 
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></TD
 
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></TR
 
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></TABLE
 
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><HR
 
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ALIGN="LEFT"
 
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WIDTH="100%"></DIV
 
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><DIV
 
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CLASS="sect1"
 
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><H1
 
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CLASS="sect1"
 
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><A
 
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NAME="section4.8"
 
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>4.8. The <SPAN
 
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CLASS="markup"
 
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>Description</SPAN
 
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> class</A
 
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></H1
 
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><A
 
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NAME="DescriptionClassDescr"
 
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></A
 
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><P
 
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>The instances of the <SAMP
 
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CLASS="computeroutput"
 
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>Description</SAMP
 
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> class provide
 
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            a description of the structure of a table.
 
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          </P
 
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><P
 
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>An instance of this class is automatically bound to
 
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            <SAMP
 
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CLASS="computeroutput"
 
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>Table</SAMP
 
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> (see <A
 
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HREF="x2981.html#TableClassDescr"
 
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>4.6</A
 
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>)
 
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            objects when they are created.  It provides a browseable
 
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            representation of the structure of the table, made of
 
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            non-nested (<SAMP
 
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CLASS="computeroutput"
 
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>Col</SAMP
 
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> &#8212;see <A
 
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HREF="x4389.html#ColClassDescr"
 
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>4.16.2</A
 
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>) and nested
 
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            (<SAMP
 
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CLASS="computeroutput"
 
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>Description</SAMP
 
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>) columns.  It also contains
 
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            information that will allow you to build
 
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            <SAMP
 
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CLASS="computeroutput"
 
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>NestedRecArray</SAMP
 
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> (see <A
 
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HREF="a6736.html#NestedRecArrayClassDescr"
 
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>appendix�B</A
 
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>) objects
 
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            suited for the different columns in a table (be they nested
 
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            or not).
 
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          </P
 
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><P
 
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>Column descriptions (see <SAMP
 
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CLASS="computeroutput"
 
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>Col</SAMP
 
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> class in <A
 
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HREF="x4389.html#ColClassDescr"
 
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>4.16.2</A
 
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>) under a description can be
 
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            accessed as attributes of it.  For instance, if
 
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            <SAMP
 
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CLASS="computeroutput"
 
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>table.description</SAMP
 
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> is a <SAMP
 
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CLASS="computeroutput"
 
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>Description</SAMP
 
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>
 
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            instance with a column named <SAMP
 
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CLASS="computeroutput"
 
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>col1</SAMP
 
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> under it, the
 
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            later can be accessed as
 
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            <SAMP
 
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CLASS="computeroutput"
 
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>table.description.col1</SAMP
 
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>.  If <SAMP
 
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CLASS="computeroutput"
 
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>col1</SAMP
 
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>
 
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            is nested and contains a <SAMP
 
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CLASS="computeroutput"
 
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>col2</SAMP
 
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> column, this can
 
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            be accessed as <SAMP
 
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CLASS="computeroutput"
 
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>table.description.col1.col2</SAMP
 
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>.
 
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          </P
 
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><DIV
 
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CLASS="sect2"
 
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><H2
 
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CLASS="sect2"
 
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><A
 
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NAME="subsection4.8.1"
 
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>4.8.1. <SPAN
 
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CLASS="markup"
 
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>Description</SPAN
 
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> instance
 
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              variables</A
 
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></H2
 
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><DIV
 
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CLASS="glosslist"
 
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><DL
 
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><DT
 
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><B
 
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>_v_name</B
 
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></DT
 
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><DD
 
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><P
 
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>The name of this description
 
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                instance.  If description is the root of the nested type
 
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                (or the description of a flat table), its name will be
 
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                the empty string (<SAMP
 
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CLASS="computeroutput"
 
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>''</SAMP
 
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>).
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_names</B
 
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></DT
 
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><DD
 
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><P
 
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>A list of the names of the
 
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                columns hanging directly from this description instance.
 
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                The order of the names matches the order of their
 
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                respective columns in the containing description.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_pathnames</B
 
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></DT
 
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><DD
 
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><P
 
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>A list of the pathnames of
 
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                the columns hanging directly from this description.  If
 
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                the table does not contain nested columns, this is
 
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                exactly the same as <SAMP
 
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CLASS="computeroutput"
 
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>_v_names</SAMP
 
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> attribute.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_nestedNames</B
 
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></DT
 
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><DD
 
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><P
 
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>A nested list of the
 
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                names of all the columns hanging directly from this
 
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                description instance.  You can use this for the
 
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                <SAMP
 
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CLASS="computeroutput"
 
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>names</SAMP
 
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> argument of
 
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                <SAMP
 
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CLASS="computeroutput"
 
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>NestedRecArray</SAMP
 
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> factory functions.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_nestedFormats</B
 
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></DT
 
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><DD
 
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><P
 
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>A nested list of the
 
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                numarray string formats (and shapes) of all the columns
 
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                hanging directly from this description instance.  You
 
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                can use this for the <SAMP
 
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CLASS="computeroutput"
 
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>formats</SAMP
 
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> argument of
 
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                <SAMP
 
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CLASS="computeroutput"
 
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>NestedRecArray</SAMP
 
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> factory functions.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_nestedDescr</B
 
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></DT
 
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><DD
 
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><P
 
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>A nested list of pairs
 
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                of <SAMP
 
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CLASS="computeroutput"
 
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>(name, format)</SAMP
 
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> tuples for all the
 
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                columns under this table or nested column.  You can use
 
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                this for the <SAMP
 
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CLASS="computeroutput"
 
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>descr</SAMP
 
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> argument of
 
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                <SAMP
 
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CLASS="computeroutput"
 
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>NestedRecArray</SAMP
 
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> factory functions.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_types</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the names
 
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                of non-nested columns hanging directly from this
 
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                description instance to their respective numarray types.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_stypes</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the
 
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                names of non-nested columns hanging directly from this
 
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                description instance to their respective string types.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_shapes</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the
 
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                names of non-nested columns hanging directly from this
 
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                description instance to their respective shapes.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_dflts</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the names
 
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                of non-nested columns hanging directly from this
 
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                description instance to their respective default values.
 
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                Please, note that all the default values are kept
 
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                internally as numarray objects.
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_colObjects</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the
 
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                names of the columns hanging directly from this
 
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                description instance to their respective descriptions
 
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                (<SAMP
 
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CLASS="computeroutput"
 
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>Col</SAMP
 
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> &#8212;see <A
 
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HREF="x4389.html#ColClassDescr"
 
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>4.16.2</A
 
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>&#8212; or
 
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                <SAMP
 
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CLASS="computeroutput"
 
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>Description</SAMP
 
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> &#8212;see <A
 
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HREF="x3623.html#DescriptionClassDescr"
 
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>4.8</A
 
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>&#8212; instances).
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_itemsizes</B
 
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></DT
 
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><DD
 
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><P
 
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>A dictionary mapping the
 
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                names of non-nested columns hanging directly from this
 
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                description instance to their respective item size (in
 
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                bytes).
 
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              </P
 
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></DD
 
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><DT
 
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><B
 
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>_v_nestedlvl</B
 
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></DT
 
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><DD
 
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><P
 
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>The level of the
 
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                description in the nested datatype.
 
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              </P
 
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></DD
 
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></DL
 
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></DIV
 
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></DIV
 
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><DIV
 
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CLASS="sect2"
 
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><H2
 
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CLASS="sect2"
 
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><A
 
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NAME="subsection4.8.2"
 
384
>4.8.2. <SPAN
 
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CLASS="markup"
 
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>Description</SPAN
 
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> methods</A
 
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></H2
 
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><DIV
 
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CLASS="glosslist"
 
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><DL
 
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><DT
 
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><B
 
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>_v_walk(type='All')</B
 
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></DT
 
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><DD
 
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><P
 
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>&#13;          </P
 
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><P
 
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>Iterate over nested columns.</P
 
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><P
 
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> </P
 
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><P
 
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>If
 
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                  <SAMP
 
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CLASS="computeroutput"
 
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>type</SAMP
 
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> is <SAMP
 
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CLASS="computeroutput"
 
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>'All'</SAMP
 
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> (the default),
 
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                  all column description objects (<SAMP
 
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CLASS="computeroutput"
 
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>Col</SAMP
 
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> and
 
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                  <SAMP
 
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CLASS="computeroutput"
 
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>Description</SAMP
 
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> instances) are returned in
 
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                  top-to-bottom order (pre-order).
 
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                </P
 
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><P
 
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>&#13;          </P
 
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><P
 
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>If <SAMP
 
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CLASS="computeroutput"
 
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>type</SAMP
 
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> is <SAMP
 
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CLASS="computeroutput"
 
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>'Col'</SAMP
 
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> or
 
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                  <SAMP
 
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CLASS="computeroutput"
 
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>'Description'</SAMP
 
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>, only column descriptions
 
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                  of that type are returned.
 
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                </P
 
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><P
 
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>&#13;        </P
 
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></DD
 
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></DL
 
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></DIV
 
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></DIV
 
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></DIV
 
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><DIV
 
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CLASS="NAVFOOTER"
 
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><HR
 
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ALIGN="LEFT"
 
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WIDTH="100%"><TABLE
 
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SUMMARY="Footer navigation table"
 
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WIDTH="100%"
 
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BORDER="0"
 
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CELLPADDING="0"
 
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CELLSPACING="0"
 
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><TR
 
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><TD
 
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WIDTH="33%"
 
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ALIGN="left"
 
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VALIGN="top"
 
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><A
 
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HREF="x3528.html"
 
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ACCESSKEY="P"
 
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>Prev</A
 
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></TD
 
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><TD
 
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WIDTH="34%"
 
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ALIGN="center"
 
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VALIGN="top"
 
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><A
 
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HREF="index.html"
 
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ACCESSKEY="H"
 
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>Home</A
 
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></TD
 
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><TD
 
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WIDTH="33%"
 
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ALIGN="right"
 
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VALIGN="top"
 
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><A
 
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HREF="x3737.html"
 
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ACCESSKEY="N"
 
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>Next</A
 
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></TD
 
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></TR
 
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><TR
 
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><TD
 
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WIDTH="33%"
 
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ALIGN="left"
 
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VALIGN="top"
 
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>The <SPAN
 
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CLASS="markup"
 
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>Cols</SPAN
 
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> class</TD
 
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><TD
 
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WIDTH="34%"
 
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ALIGN="center"
 
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VALIGN="top"
 
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><A
 
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HREF="c1381.html"
 
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ACCESSKEY="U"
 
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>Up</A
 
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></TD
 
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><TD
 
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WIDTH="33%"
 
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ALIGN="right"
 
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VALIGN="top"
 
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>The <SPAN
 
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CLASS="markup"
 
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>Column</SPAN
 
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> class</TD
 
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></TR
 
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></TABLE
 
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></DIV
 
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></BODY
 
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></HTML
 
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>
 
 
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