Examination marks data set

Description

Examination marks of 88 students on five different topics, from Mardia (1979).

Usage

data(marks)

Format

The marks data set contains the following variables, one for each topic in the examination:

• MECH (mechanics)

• VECT (vectors)

• ALG (algebra)

• ANL (analysis)

• STAT (statistics)

All are measured on the same scale (0-100).

Source

Edwards DI (2000). Introduction to Graphical Modelling. Springer, 2nd edition.

Mardia KV, Kent JT, Bibby JM (1979). Multivariate Analysis. Academic Press.

Whittaker J (1990). Graphical Models in Applied Multivariate Statistics. Wiley.

Examples

# This is the undirected graphical model from Edwards (2000).
data(marks)
ug = empty.graph(names(marks))
arcs(ug, check.cycles = FALSE) = matrix(
  c("MECH", "VECT", "MECH", "ALG", "VECT", "MECH", "VECT", "ALG",
    "ALG",  "MECH", "ALG", "VECT", "ALG",  "ANL", "ALG",  "STAT",
    "ANL",  "ALG", "ANL",  "STAT", "STAT", "ALG", "STAT", "ANL"),
  ncol = 2, byrow = TRUE,
  dimnames = list(c(), c("from", "to")))
## Not run: graphviz.plot(ug)