# subset: Subsetting 'incidence' objects In incidence: Compute, Handle, Plot and Model Incidence of Dated Events

## Description

Two functions can be used to subset incidence objects. The function `subset` permits to retain dates within a specified range and, optionally, specific groups. The operator "[" can be used as for matrices, using the syntax `x[i,j]` where 'i' is a subset of dates, and 'j' is a subset of groups.

## Usage

 ```1 2 3 4 5``` ```## S3 method for class 'incidence' subset(x, ..., from = min(x\$dates), to = max(x\$dates), groups = TRUE) ## S3 method for class 'incidence' x[i, j] ```

## Arguments

 `x` An incidence object, generated by the function `incidence()`. `...` Further arguments passed to other methods (not used). `from` The starting date; data strictly before this date are discarded. `to` The ending date; data strictly after this date are discarded. `groups` (optional) The groups to retained, indicated as subsets of the columns of x\$counts. `i` a subset of dates to retain `j` a subset of groups to retain

## Author(s)

Thibaut Jombart thibautjombart@gmail.com

The `incidence()` function to generate the 'incidence' objects.
 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```## example using simulated dataset if(require(outbreaks)) { withAutoprint({ onset <- ebola_sim\$linelist\$date_of_onset ## weekly incidence inc <- incidence(onset, interval = 7) inc inc[1:10] # first 10 weeks plot(inc[1:10]) inc[-c(11:15)] # remove weeks 11-15 plot(inc[-c(11:15)]) })} ```