mlogit (version 0.1-0)

mlogit.data: data.frame for logit model

Description

shape a data.frame in a suitable form for the use of the mlogit function.

Usage

mlogit.data(x, choice, cvar = NULL, shape = "vert",
            alt = NULL, chid = NULL, opposite = NULL, ...)

Arguments

x

a data.frame,

choice

the variable indicating the choice made,

cvar

a named vector indicating in which columns start a choice-specific variable if data are stored ``vertically'',

shape

if equal to hor.var or hor.alt, there is one row for each choice and each column contains a variable for an alternative (the columns are ordered by variable in the first case and by alternative in the second case). If

alt

if shape is equal to hor.var or hor.alt, it may be NULL. In this case, the levels of the choice variables are assumed to be in the same order as the subsequent columns representing the choice-specific var

chid

the choice index, only relevant if shape='vert',

opposite

returns the opposite of the specified variables,

...

further arguments.

Value

• A data.frame with a line for every alternative.

Details

The first column is a variable that identifies the choice, whether auto-generated and called chid or provided with the chid argument. The second column identifies the alternatives. It is provided with the alt argument or is auto-generated. In this later case, its name is alt.

Examples

# ModeChoice is a vertical shaped data.frame 

data("ModeChoice",package="Ecdat")
ModeChoice <- mlogit.data(ModeChoice,choice="mode",shape="vert",
                 alt=c("air","train","bus","car"))

# Same but with an alt variable called altm

data("ModeChoice",package="Ecdat")
ModeChoice$altm <- rep(c("air","train","bus","car"),210)
ModeChoice <- mlogit.data(ModeChoice,choice="mode",shape="vert",
                 alt="altm")

# Same but with an chid variable called ind 

data("ModeChoice",package="Ecdat")
ModeChoice$ind <- rep(1:210,each=4)
ModeChoice <- mlogit.data(ModeChoice,choice="mode",shape="vert",
                 chid="ind",alt=c("air","train","bus","car"))

# Same but with two own provided variables

data("ModeChoice",package="Ecdat")
ModeChoice$ind <- rep(1:210,each=4)
ModeChoice$altm <- rep(c("air","train","bus","car"),210)
ModeChoice <- mlogit.data(ModeChoice,choice="mode",shape="vert",
                 chid="ind",alt="altm")


# Train is an horizontal shaped data.frame with columns ordered by
# alternatives, 'choiceid' is the choice index

data("Train",package="Ecdat")
Train <- mlogit.data(Train,choice="choice",shape="hor.alt",
                 cvar=c(price=4,time=5,change=6,comfort=7),
                 opposite=c("price","time","change","comfort"),chid="choiceid")

# Car is an horizontal data.frame with columns ordered by variables

data("Car",package="Ecdat")
Car <- mlogit.data(Car,cvar=c(type=5,fuel=11,price=17,range=23,acc=29,speed=35,
                 pollution=41,size=47,space=53,cost=59,station=65),
                 shape="hor.var",choice="choice")