The goal of longmixr is to provide consensus clustering for
longitudinal clustering performed with `flexmix`

.
It uses the approach from `ConsensusClusterPlus`

but replaces the clustering of the longitudinal data with a
`flexmix`

model.

You can install longmixr from github with:

`::install_github("cellmapslab/longmixr") remotes`

If you want to render the vignette, use:

`::install_github("cellmapslab/longmixr", build_vignettes = TRUE, dependencies = TRUE) remotes`

Please note that for the vignette a lot more dependencies are installed.

You need a dataset with a column that identifies the subject, a column that denotes the time point of the measurement and variables that you want to model.

```
set.seed(5)
<- data.frame(
test_data patient_id = rep(1:10, each = 4),
visit = rep(1:4, 10),
var_1 = c(rnorm(20, -1), rnorm(20, 3)) + rep(seq(from = 0, to = 1.5, length.out = 4), 10),
var_2 = c(rnorm(20, 0.5, 1.5), rnorm(20, -2, 0.3)) + rep(seq(from = 1.5, to = 0, length.out = 4), 10)
)
```

In the following approach, the variables `var_1`

and
`var_2`

each are modeled as dependent on a smooth function of
time, taking the multiple measurements for each subject into account.
The assumption is that `var_1`

and `var_2`

represent a multivariate outcome. The modeling is specified in the
`flexmix`

drivers and the `flexmix_formula`

:

```
<- list(flexmix::FLXMRmgcv(as.formula("var_1 ~ .")),
model_list ::FLXMRmgcv(as.formula("var_2 ~ .")))
flexmix<- longitudinal_consensus_cluster(
clustering data = test_data,
id_column = "patient_id",
max_k = 2,
reps = 3,
model_list = model_list,
flexmix_formula = as.formula("~s(visit, k = 4) | patient_id"))
```

The results of the clustering can be assessed via several plots. For every specified number of clusters, the consensus matrix and the resulting hierarchical clustering on this matrix is shown. Additionally, the consensus CDF and the delta Area plots give a measure which number of cluster is optimal. The tracking plot gives an overview how the observations are distributed across the different clusters for different numbers of specified clusters. The item (subject) consensus plot shows the average consensus of each subject with all other subjects that belong to one cluster. The cluster consensus plot depicts the average consensus between all members of each cluster.

The above mentioned plots are generated when calling the
`plot`

function:

`plot(clustering)`

For a detailed explanation how you can use `longmixr`

to
analyze your longitudinal data, check out the Example
clustering analysis vignette.

Additionally, this package provides a wrapper function around the
`ConsensusClusterPlus`

function to work with mixed continuous
and categorical data (by using the Gower distance):

```
<- mtcars
dc # scale continuous variables
<- sapply(mtcars[, 1:7], scale)
dc # code factor variables
<- cbind(as.data.frame(dc),
dc vs = as.factor(mtcars$vs),
am = as.factor(mtcars$am),
gear = as.factor(mtcars$gear),
carb = as.factor(mtcars$carb))
<- crosssectional_consensus_cluster(
cc data = dc,
reps = 10,
seed = 1
)
```

The package is based on the code of `ConsensusClusterPlus`

(version 1.52.0). For this code the copyright holders are Matt Wilkerson
and Peter Waltman. For all subsequent changes the copyright holder is
the Max Planck Institute of Psychiatry. The code is licensed under GPL
v2.