syncevents
Add and synchronize variables from attached event table to timetable
Since R2023a
Syntax
Description
TT2 = syncevents(
adds the variables from
the attached event table to the main timetable and synchronizes them. The new variables of
the timetable have values from the corresponding variables of the event table in the
timetable rows that occur during events. The new variables have missing values in the
timetable rows without events.TT
)
If the attached events table has an event labels variable, then
syncevents
adds the variable to the timetable. This new timetable variable also has missing values in the rows without events.If the attached events table has an event lengths or event end times variable, then
syncevents
does not add the variable to the timetable. These event table variables are indicated by theEventLengthsVariable
and theEventEndsVariable
properties of the attached event table.If the events have lengths or end times, then it is possible for events to overlap. If events overlap, then
syncevents
creates duplicate rows in the output timetable for those events. In that case, the output timetable is irregular even if the input timetable is regular.
TT2 = syncevents(
specifies TT
,defaultLabel
)defaultLabel
as the event label for timetable rows without
events instead of using missing values.
Examples
Synchronize Events to Timetable
When a timetable has an attached event table, you can use the syncevents
function to synchronize events from the event table to the timetable.
First, load a timetable and an event table from a sample MAT-file. Then display the timetable. It has data for weather conditions spanning two weeks.
load weatherEvents.mat
weatherData
weatherData=15×2 timetable
Time Temperature Humidity
___________ ___________ ________
01-Nov-2022 36 45
02-Nov-2022 31 76
03-Nov-2022 37 43
04-Nov-2022 36 46
05-Nov-2022 38 72
06-Nov-2022 32 54
07-Nov-2022 35 50
08-Nov-2022 34 45
09-Nov-2022 32 72
10-Nov-2022 30 58
11-Nov-2022 39 54
12-Nov-2022 34 58
13-Nov-2022 31 73
14-Nov-2022 40 78
15-Nov-2022 34 66
Display the event table. It has event times, event labels, event lengths, and precipitation measurements for weather events that occurred during that two-week span. In this event table, the EventType
variable contains the event labels.
weatherEvents
weatherEvents = 4x3 eventtable
Event Labels Variable: EventType
Event Lengths Variable: EventLength
Time EventType EventLength Precipitation (mm)
___________ _________ ___________ __________________
03-Nov-2022 Hail 1.2 hr 12.7
05-Nov-2022 Rain 36 hr 114.3
10-Nov-2022 Snow 18 hr 25.4
14-Nov-2022 Rain 20 hr 177.8
Attach the event table to the timetable.
weatherData.Properties.Events = weatherEvents
weatherData=15×2 timetable
Time Temperature Humidity
___________ ___________ ________
01-Nov-2022 36 45
02-Nov-2022 31 76
Hail 03-Nov-2022 37 43
04-Nov-2022 36 46
Rain 05-Nov-2022 38 72
Rain 06-Nov-2022 32 54
07-Nov-2022 35 50
08-Nov-2022 34 45
09-Nov-2022 32 72
Snow 10-Nov-2022 30 58
11-Nov-2022 39 54
12-Nov-2022 34 58
13-Nov-2022 31 73
Rain 14-Nov-2022 40 78
15-Nov-2022 34 66
To synchronize the events from the attached event table to the timetable, use syncevents
. The output timetable has a new variable with event labels in the rows whose row times match event times. The syncevents
function inserts missing values in the new variables where the row times do not match any events. In this example, the missing values in EventType
are <undefined>
categorical values because EventType
is a categorical
variable. The missing values are NaN
s in the precipitation data.
weatherData = syncevents(weatherData)
weatherData=15×4 timetable
Time Temperature Humidity EventType Precipitation (mm)
___________ ___________ ________ ___________ __________________
01-Nov-2022 36 45 <undefined> NaN
02-Nov-2022 31 76 <undefined> NaN
Hail 03-Nov-2022 37 43 Hail 12.7
04-Nov-2022 36 46 <undefined> NaN
Rain 05-Nov-2022 38 72 Rain 114.3
Rain 06-Nov-2022 32 54 Rain 114.3
07-Nov-2022 35 50 <undefined> NaN
08-Nov-2022 34 45 <undefined> NaN
09-Nov-2022 32 72 <undefined> NaN
Snow 10-Nov-2022 30 58 Snow 25.4
11-Nov-2022 39 54 <undefined> NaN
12-Nov-2022 34 58 <undefined> NaN
13-Nov-2022 31 73 <undefined> NaN
Rain 14-Nov-2022 40 78 Rain 177.8
15-Nov-2022 34 66 <undefined> NaN
Specify Label for Rows Without Events
When you synchronize events to a timetable, you can specify a label for the rows that do not correspond to any events. You can use the new label instead of missing values to mark such rows.
First, load a timetable and an event table from a sample MAT-file. Display the event table. It has labels for times when hail, rain, or snow occurred.
load weatherEvents.mat
weatherEvents
weatherEvents = 4x3 eventtable
Event Labels Variable: EventType
Event Lengths Variable: EventLength
Time EventType EventLength Precipitation (mm)
___________ _________ ___________ __________________
03-Nov-2022 Hail 1.2 hr 12.7
05-Nov-2022 Rain 36 hr 114.3
10-Nov-2022 Snow 18 hr 25.4
14-Nov-2022 Rain 20 hr 177.8
Attach the event table to the timetable.
weatherData.Properties.Events = weatherEvents
weatherData=15×2 timetable
Time Temperature Humidity
___________ ___________ ________
01-Nov-2022 36 45
02-Nov-2022 31 76
Hail 03-Nov-2022 37 43
04-Nov-2022 36 46
Rain 05-Nov-2022 38 72
Rain 06-Nov-2022 32 54
07-Nov-2022 35 50
08-Nov-2022 34 45
09-Nov-2022 32 72
Snow 10-Nov-2022 30 58
11-Nov-2022 39 54
12-Nov-2022 34 58
13-Nov-2022 31 73
Rain 14-Nov-2022 40 78
15-Nov-2022 34 66
Synchronize the events to the timetable using syncevents
. Specify "No Storm"
as the label for the rows when no hail, rain, or snow occurred. Because EventType
is a categorical
variable, syncevents
converts the string to a new category named No Storm
.
weatherData = syncevents(weatherData,"No Storm")
weatherData=15×4 timetable
Time Temperature Humidity EventType Precipitation (mm)
___________ ___________ ________ _________ __________________
01-Nov-2022 36 45 No Storm NaN
02-Nov-2022 31 76 No Storm NaN
Hail 03-Nov-2022 37 43 Hail 12.7
04-Nov-2022 36 46 No Storm NaN
Rain 05-Nov-2022 38 72 Rain 114.3
Rain 06-Nov-2022 32 54 Rain 114.3
07-Nov-2022 35 50 No Storm NaN
08-Nov-2022 34 45 No Storm NaN
09-Nov-2022 32 72 No Storm NaN
Snow 10-Nov-2022 30 58 Snow 25.4
11-Nov-2022 39 54 No Storm NaN
12-Nov-2022 34 58 No Storm NaN
13-Nov-2022 31 73 No Storm NaN
Rain 14-Nov-2022 40 78 Rain 177.8
15-Nov-2022 34 66 No Storm NaN
Copy Event Data Variables to Timetable
Event tables can have event data variables that contain additional data about events. When you synchronize events to a timetable, the syncevents
function copies all additional event data variables to the output timetable. You can use the EventDataVariables
name-value argument to choose which event data variables to copy. For instance, you can include event lengths or event end times in the output timetable, or exclude event labels or additional event data variables.
First, load a timetable and an event table from a sample MAT-file. Display the event table.
load weatherEvents.mat
weatherEvents
weatherEvents = 4x3 eventtable
Event Labels Variable: EventType
Event Lengths Variable: EventLength
Time EventType EventLength Precipitation (mm)
___________ _________ ___________ __________________
03-Nov-2022 Hail 1.2 hr 12.7
05-Nov-2022 Rain 36 hr 114.3
10-Nov-2022 Snow 18 hr 25.4
14-Nov-2022 Rain 20 hr 177.8
Attach the event table to the timetable.
weatherData.Properties.Events = weatherEvents
weatherData=15×2 timetable
Time Temperature Humidity
___________ ___________ ________
01-Nov-2022 36 45
02-Nov-2022 31 76
Hail 03-Nov-2022 37 43
04-Nov-2022 36 46
Rain 05-Nov-2022 38 72
Rain 06-Nov-2022 32 54
07-Nov-2022 35 50
08-Nov-2022 34 45
09-Nov-2022 32 72
Snow 10-Nov-2022 30 58
11-Nov-2022 39 54
12-Nov-2022 34 58
13-Nov-2022 31 73
Rain 14-Nov-2022 40 78
15-Nov-2022 34 66
Synchronize the events to the timetable. By default, syncevents
does not copy event lengths or event end times to the output timetable. In this example, specify the EventLength
variable as an event data variable to copy. Specify Precipitation (mm)
as another event data variable. The syncevents
function inserts missing values in timetable rows that do not occur during events. The timetable displays event labels even though EventType
is not copied to the timetable. The event labels are still in the attached event table, so they are still displayed next to the matching timetable rows.
weatherData = syncevents(weatherData,EventDataVariables=["EventLength","Precipitation (mm)"])
weatherData=15×4 timetable
Time Temperature Humidity EventLength Precipitation (mm)
___________ ___________ ________ ___________ __________________
01-Nov-2022 36 45 NaN hr NaN
02-Nov-2022 31 76 NaN hr NaN
Hail 03-Nov-2022 37 43 1.2 hr 12.7
04-Nov-2022 36 46 NaN hr NaN
Rain 05-Nov-2022 38 72 36 hr 114.3
Rain 06-Nov-2022 32 54 36 hr 114.3
07-Nov-2022 35 50 NaN hr NaN
08-Nov-2022 34 45 NaN hr NaN
09-Nov-2022 32 72 NaN hr NaN
Snow 10-Nov-2022 30 58 18 hr 25.4
11-Nov-2022 39 54 NaN hr NaN
12-Nov-2022 34 58 NaN hr NaN
13-Nov-2022 31 73 NaN hr NaN
Rain 14-Nov-2022 40 78 20 hr 177.8
15-Nov-2022 34 66 NaN hr NaN
Input Arguments
TT
— Input timetable
timetable
Input timetable. TT
must have an event table attached to its
Events
property. In other words,
TT.Properties.Events
must contain an event table.
defaultLabel
— Label for rows without events
scalar
Label for rows without events, specified as a scalar. The data type of
defaultLabel
must be compatible with the data type of the
EventLabelsVariable
of the event table that is attached to
TT
.
Example: TT = syncevents(TT,"N/A")
adds event labels from the
event table attached to TT
and adds "N/A"
as the
label for rows of TT
that do not correspond to events.
vars
— Variables to copy from attached event table
string array | character vector | pattern
scalar | numeric array | logical array
Variables to copy from the attached event table, specified as a string array,
character vector, pattern
scalar, numeric array, or logical array.
Version History
Introduced in R2023a
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