tt = horzcat (tt1, tt2, …) appends the variables of its inputs, which must all have distinct variable names and, where they are timetables, identical row times. It is the operation [tt1, tt2] performs.

A table may be appended to a timetable, but only after it, and it must have as many rows as the timetable has. The row times and the time step are those of the timetable, and the row dimension is named after the first input that does not use the default name.

Where an operand is an eventtable, or carries one on its Events property, the result is an event table too and the operands’ event tables are merged: an outer join keyed on the event times and every variable the two share, ordered by those keys. The three properties saying which variables describe the events must agree, and the operation is refused where they do not.

See also: vertcat, cat

Source Code: timetable