# synchronize

Synchronize timetables to common time vector, and resample or aggregate data from input timetables

## Syntax

## Description

The `synchronize`

function collects the variables from all
input timetables, synchronizes them to a common time vector, and returns the result as a
single timetable. The effect is similar to a horizontal concatenation, though the input
timetables can have different row times. When the `synchronize`

function synchronizes timetable variables to different times, it also resamples or
aggregates the data in the variables using a method that you specify.

`TT = synchronize(`

creates a
timetable, `TT1,TT2`

)`TT`

, that contains all variables from both the
input timetables `TT1`

and `TT2`

, synchronized
to a vector of row times that is the union of the row times from
`TT1`

and `TT2`

. The row times of
`TT`

are in sorted order with no repeated times.

In effect, `synchronize`

horizontally concatenates the
variables of `TT1`

and `TT2`

, even when they
have row times that differ. As a result, `synchronize`

inserts
a missing data indicator in `TT`

wherever it has:

A row time only from

`TT1`

but no corresponding data from the variables of`TT2`

.A row time only from

`TT2`

but no corresponding data from the variables of`TT1`

.

If `TT1`

and `TT2`

have variables with the
same names, then `synchronize`

renames them and copies both
variables into `TT`

.

To interpolate or fill in values in `TT`

using different
methods for different variables, specify the
`VariableContinuity`

property of each input timetable. For
more information, see Retime and Synchronize Timetable Variables Using Different Methods.

`TT = synchronize(`

creates `TT1,TT2`

,`newTimeBasis`

,`method`

)`TT`

by synchronizing the variables from
`TT1`

and `TT2`

to a new time vector
specified by `newTimeBasis`

. `synchronize`

resamples or aggregates data from the variables in `TT1`

and
`TT2`

using the operation specified by
`method`

. The input argument,
`newTimeBasis`

, specifies how
`synchronize`

constructs the row times of
`TT`

from the row times of `TT1`

and
`TT2`

.

For example, if `newTimeBasis`

is `'union'`

and `method`

is `'linear'`

, then
`TT`

contains the row times from `TT1`

and
`TT2`

, and `synchronize`

uses linear
interpolation to resample the data from the input timetables to the output row
times.

`TT = synchronize(`

creates `TT1,TT2`

,`newTimeStep`

,`method`

)`TT`

by synchronizing the variables from
`TT1`

and `TT2`

to a new time vector that
is regularly spaced by the time unit specified by
`newTimeStep`

.

For example, if `newTimeStep`

is `'daily'`

and `method`

is `'mean'`

, then
`TT`

contains row times that are one day apart, and
`TT`

contains daily means for each variable from
`TT1`

and `TT2`

.

`TT = synchronize(`

creates `TT1,TT2`

,`newTimeBasis`

)`TT`

by synchronizing the variables from
`TT1`

and `TT2`

to a new time vector.
`synchronize`

inserts missing data indicators where needed
in `TT`

.

`TT = synchronize(`

creates `TT1,TT2`

,`newTimeStep`

)`TT`

by synchronizing the variables from
`TT1`

and `TT2`

to a new time vector that
is regularly spaced by the time unit specified by
`newTimeStep`

. The `synchronize`

function
inserts missing data indicators where needed in `TT`

.

`TT = synchronize(`

synchronizes timetables with additional options specified by one or more
`TT1,TT2`

,___,`Name,Value`

)`Name,Value`

pairs. You can use this syntax with the input
arguments of any of the previous syntaxes.

`TT = synchronize(TT1,...,TTN,___)`

creates the
timetable, `TT`

, by synchronizing the `N`

timetables `TT1,...,TTN`

. You can use this syntax with the
input arguments of any of the previous syntaxes.

## Examples

## Input Arguments

## Extended Capabilities

## Version History

**Introduced in R2016b**

## See Also

`innerjoin`

| `retime`

| `outerjoin`

| `horzcat`

| `vertcat`

| `synchronize`

| Retime Timetable | Synchronize
Timetables

### Topics

- Clean Timetable with Missing, Duplicate, or Nonuniform Times
- Resample and Aggregate Data in Timetable
- Combine Timetables and Synchronize Their Data
- Retime and Synchronize Timetable Variables Using Different Methods
- Calculations When Tables Have Both Numeric and Nonnumeric Data
- Grouped Calculations in Tables and Timetables
- Add Event Table from External Data to Timetable