# Introduction

In this vignette we will explore the functionality and arguments of a
set of functions that will help us to understand and visualise the
temporal symmetry results (produced **Step 4: Obtain aggregated
data on temporal symmetry**). In particular, we will delve into
the following function:

`plotTemporalSymmetry()`

: to plot the temporal
symmetry.

This function builds-up on previous functions, such as
`generateSequenceCohortSet()`

and
`summariseTemporalSymmetry()`

function.

Let’s regather the output from
`summariseTemporalSymmetry()`

`temporal_symmetry <- summariseTemporalSymmetry(cohort = cdm$intersect)`

With this established, much like
`summariseSequenceRatios()`

, the object
`temporal_symmetry`

could then be fed into
`summariseTemporalSymmetry()`

to visualise the results:

`plotTemporalSymmetry(result = temporal_symmetry)`

Note that the \(x\) axis is the time,
which we recall to be the initiation of the marker minus the initiation
of the index. The unit of the time difference here is month as this is
the default from `summarisTemporalSymmetry()`

.

## Modify `xlim`

and `labs`

If one changes the `timescale`

for
`summarisTemporalSymmetry()`

to be `day`

then
logically one should change the `xlim`

and `labs`

accordingly like so:

```
temporal_symmetry_day <- summariseTemporalSymmetry(cohort = cdm$intersect, timescale = "day")
plotTemporalSymmetry(result = temporal_symmetry_day,
labs = c("Time (days)", "Individuals (N)"),
xlim = c(-365, 365))
```

## Modify `plotTitle`

Much like what we already saw in **Step 3. Visualise the
sequence ratios**. One could do the following:

```
plotTemporalSymmetry(result = temporal_symmetry,
plotTitle = "Plot Temporal Symmetry")
```

## Modify `colours`

`colours`

could be modified like so (remember two colours
are required):

```
plotTemporalSymmetry(result = temporal_symmetry,
colours = c("orange", "purple"))
```

## Modify `scales`

The `scale`

parameter is designed for the users to have a
choice as to whether to set free y scales for the facet wrap when there
are multiple plots (i.e. each plot has its own scaled y axis) or set
them equal for all. Only accepts “free” for the former and “fixed” for
the latter.

For the `cdm$intersect`

we have, it does not make a
difference setting it to “fixed” or “free” (default). However, should
one wish to set it to “fixed”, one should do:

```
plotTemporalSymmetry(result = temporal_symmetry,
scales = "fixed")
```

`CDMConnector::cdmDisconnect(cdm = cdm)`

**That would be the end of the vignette, have fun with the
package!**