MATLAB Programming Fundamentals - MathWorks

Using Row Labels in Table and Timetable Operations

Tables and timetables provide ways to label the rows in your data. In tables, you can label

the rows with names. In timetables, you must label the rows with dates, times, or both.

Row names are optional for tables, but row times are required for timetables. These row

labels are part of the metadata in a table or timetable. In some functions you also can use

row labels as key variables, grouping variables, and so on, just as you can use the data

variables in a table or timetable. These functions are sortrows, join, innerjoin,

outerjoin, varfun, rowfun, stack, and unstack. There are some limitations on using

these table functions and on using row labels as key variables.

Sort on Row Labels

For example, you can sort a timetable on its row times, on one or more of its data

variables, or on row times and data variables together.

Create a timetable using the timetable function. A timetable has row times along its

first dimension, labeling the rows. The row times are a property of the timetable, not a

timetable variable.

Date = datetime(2016,7,[10;10;11;11;10;10;11;11]);

X = [1;1;1;1;2;2;2;2];

Y = {'a';'b';'a';'b';'a';'b';'a';'b'};

Z = [1;2;3;4;5;6;7;8];

TT = timetable(X,Y,Z,'RowTimes',Date)

TT=8×4 timetable

Time X Y Z

___________ _ ___ _

10-Jul-2016 1 'a' 1

10-Jul-2016 1 'b' 2

11-Jul-2016 1 'a' 3

11-Jul-2016 1 'b' 4

10-Jul-2016 2 'a' 5

10-Jul-2016 2 'b' 6

11-Jul-2016 2 'a' 7

11-Jul-2016 2 'b' 8

Rename the first dimension. By default, the name of the first dimension of a timetable is

Time. You can access the Properties.DimensionNames property to rename a

dimension.

10 Timetables