shift.var

a <code>data.frame</code> or <code>data.table</code>

data

a character string vector of variable names; <code>id.vars</code> are used to identify unique subjects,
for which shifting is done separately; e.g. with a panel data where <code>region</code> refers to different regions that
all have their own time series

id.vars

a character string vector of length one; specifies the variable according to which <code>value.vars</code>
are shifted; e.g. <code>id.vars = "year"</code> means shifting forward or backward in years (given one has a var name <code>"year"</code>)

a character string vector; specifies the names of variables whose values that are shifted

value.vars

an integer; specifies the direction and extent of shifting; e.g. <code>shift.value = -1L</code> shifts
one row backwards (a lag of one row) and <code>shift.value = 2L</code> creates a two-row lead

shift.value

<strong>DEPRECATED</strong>: 
Intended to do what <code><a href="/link/shift?package=popEpi&version=0.3.0&to=data.table" rd-options="data.table" data-mini-rdoc="data.table::shift">shift</a></code> from
<pkg>data.table</pkg> does better since <pkg>data.table</pkg> 1.9.6. 
Shifts the values of a variable forwards or 
backwards to create lag or lead values. Takes a copy of the whole data
and returns a new copy with the shifted variable.

Enables computation of various epidemiological statistics where the use of population data such as population counts and hazards is required.
                 Relatively high computation speed achieved by using data.table.

shift.var: Shift a variable to create lag or lead values

Description

Usage

Arguments