add.design.data: Add design data

Description

Creates new design data fields in (ddl) that bin the fields cohort, age or time. Other fields (e.g., effort value for time) can be added to ddl with R commands.

Usage

add.design.data(data, ddl, parameter, type = "age", bins = NULL, name = NULL, replace = FALSE, right = TRUE)

Arguments

data

processed data list resulting from process.data

ddl

current design dataframe initially created with make.design.data

parameter

name of model parameter (e.g., "Phi" for CJS models)

type

either "age", "time" or "cohort"

bins

bins for grouping

name

name assigned to variable in design data

replace

if TRUE, replace any variable with same name as name

right

If TRUE, bin intervals are closed on the right

Value

Design data list with new field added for the specified parameter. See make.design.data for a description of the list structure.

Details

Design data can be added to the parameter specific design dataframes with R commands. Often the additional fields will be functions of cohort, age or time. add.design.data provides an easy way to add fields that bin (put into intervals) the original values of cohort, age or time. For example, age may have levels from 0 to 10 which means the formula ~age will have 11 parameters, one for each level of the factor. It might be more desirable and more parimonious to have a simpler 2 age class model of young and adults. This can be done easily by adding a new design data field that bins age into 2 intervals (age 0 and 1+) as in the following example:

 ddl=make.design.data(proc.example.data)
ddl=add.design.data(proc.example.data,ddl,parameter="Phi",type="age",
bins=c(0,.5,10),name="2ages")

By default, the bins are open on the left and closed on the right (i.e., binning x by (x1,x2] is equivalent to x10 and <1 0="" 2="" in="" place="" of="" 0.5="" would="" bin="" the="" ages="" into="" classes="" and="" 1+.="" this="" behavior="" can="" be="" modified="" by="" changing="" argument="" right="FALSE" to="" create="" an="" interval="" that="" is="" closed="" on="" left="" open right.="" some="" cases="" make="" reading="" values="" levels="" somewhat="" easier.="" it="" important="" recognize="" new="" variable="" only="" added="" design="" data="" for="" defined="" parameter and can only be used in model formula for that parameter. Multiple calls to add.design.data can be used to add the same or different fields for the various parameters in the model. For example, the same 2 age class variable can be added to the design data for p with the command:

ddl=add.design.data(proc.example.data,ddl,parameter="p",type="age",
bins=c(0,.5,10),name="2ages")

The name must be unique within the parameter design data, so they should not use pre-defined values of group, age, Age, time, Time, cohort, Cohort. If you choose a name that already exists in the design data for the parameter, it will not be added but it can replace the variable if replace=TRUE. For example, the 2ages variable can be re-defined to use 0-1 and 2+ with the command:

ddl=add.design.data(proc.example.data,ddl,parameter="Phi",type="age",
bins=c(0,1,10),name="2ages",replace=TRUE)

Keep in mind that design data are stored with the mark model object so if a variable is redefined, as above, this could become confusing if some models have already been constructed using a different definition for the variable. The model formula and names would appear to be identical but they would have a different model structure. The difference would be apparent if you examined the design data and design matrix of the model object but would the difference would be transparent based on the model names and formula. Thus, it would be best to avoid constructing models from design data fields with different structures but the same name.

Examples

Run this code


# This example is excluded from testing to reduce package check time
data(example.data)
example.data.proc=process.data(example.data)
ddl=make.design.data(example.data.proc)
ddl=add.design.data(example.data.proc,ddl,parameter="Phi",type="age",
  bins=c(0,.5,10),name="2ages")
ddl=add.design.data(example.data.proc,ddl,parameter="p",type="age",
bins=c(0,.5,10),name="2ages")
ddl=add.design.data(example.data.proc,ddl,parameter="Phi",type="age",
bins=c(0,1,10),name="2ages",replace=TRUE)