time_discretization: Time discretization function for FCM data
In rprops/Phenoflow_package: Advanced analysis of microbial flow cytometry data

This function subsets the input frames based on analysis time. Developped for analysis of on-line time series data.

time_discretization(
  x,
  analysis.length,
  create = FALSE,
  start = 0,
  time.interval,
  height = c(0, 200),
  trigger = "FL1-H",
  time.step = 0.1
)

`x`	flowSet of FCM data
`analysis.length`	Dataframe with $time defining the total analysis time for each sample
`create`	Do you want to make a new folder for the new flowframes? Defaults to FALSE.
`start`	Vector of length n(x) that indicates for each sample at what time point it should start discretisizing. (e.g., first 10 minutes are irrelevant, start = 10*60)
`time.interval`	Bin size of each new FCS file. For example, time.interval = 10 will make new FCS files of 10 second intervals.
`height`	Bottom and top of the time window utilized (use minimum and maximum parameter intensity). Default on c(0,200)
`trigger`	Primary parameter of signal detection (e.g. FL1-H for SYBR Green). This is used to construct the binning window with the height parameter.
`time.step`	discrete unit of time used in the FCS files (FCS files don't register in seconds). This value is used to transform the discrete time units into seconds.