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Tables

The Tables module provides tools for creating, accessing, and manipulating tabular data in Nelson.

Tables are array-like structures with named variables (columns), each capable of holding different data types.

Table metadata is available through T.Properties, and helper functions are provided for adding, moving, renaming, removing and summarizing variables.

Timetables store tabular variables together with row times and provide time-based sorting, retiming, synchronization, and range queries.

Create and Convert Tables

Functions for creating tables and timetables and converting between tabular and other data forms.

Read and Write Tables

Pages for reading and writing table data.

Summary Information

Functions for table size, type checks, and quick previews.

  • head
    Get top rows of table or array.
  • height
    Number of table rows
  • istable
    Determine if input is table.
  • istabular
    Determine if input is a tabular object.
  • istimetable
    Determine if input is a timetable.
  • tail
    Get bottom rows of table or array.
  • width
    Number of table variables
Sort, Filter, and Rearrange

Functions and topics for accessing, sorting, rearranging, and customizing table contents.

Join and Set Operations

Functions for combining tables with joins and related operations.

Apply Functions to Table Contents

Functions and topics for direct calculations and applying functions to table rows or variables.

Timetables and Events

Functions for timetable ranges, events, synchronization, and retiming.

  • containsrange
    Determine if timetable row times contain a time range.
  • eventtable
    Create an event table for a timetable.
  • extractevents
    Extract an event table from rows of a timetable.
  • isregular
    Determine if timetable row times are regularly spaced.
  • issortedrows
    Determine if timetable rows are sorted.
  • lag
    Shift timetable data by rows.
  • overlapsrange
    Determine if timetable row times overlap a time range.
  • retime
    Adjust timetable data to new row times.
  • syncevents
    Add and synchronize the variables of the attached event table to a timetable.
  • synchronize
    Synchronize timetables to common row times.
  • timerange
    Time range for timetable row subscripting.
  • withinrange
    Find timetable rows within a time range.
  • withtol
    Time tolerance for timetable row subscripting.