localdepth (version 0.5-7)

glasses: Roman-Venetian Glass dataset

Description

The dataset gives the compositions of 73 glass specimens excavated in a series of archeological campaign in the island of Venice lagoon and nearby borders.

Usage

data(glasses)

Format

Data frame with 73 observations on the following 14 variables.

ID

Specimens number

CLA

type of glass: 1, Venetian glass (XIVth-XVIth centuries); 2, Roman glass (Ist-Vth centuries A.D.); 3, Middle Ages glass (VIth-XIIIth centuries)

SIO2

a numeric vector

AL2O3

a numeric vector

NA2O

a numeric vector

K2O

a numeric vector

CAO

a numeric vector

MGO

a numeric vector

FE2O3

a numeric vector

TIO2

a numeric vector

P2O5

a numeric vector

CL

a numeric vector

SO3

a numeric vector

MNO

a numeric vector

Source

Mario Romanazzi.

Details

Variables SIO2 to MNO are provide composition of glass specimens on the corresponding chemical compound.

References

M. Verita', A. Renier and S. Zecchin (2002) Chemical analyses of ancient glass findings excavated in the venetian lagoon. Journal of Cultural Heritage, 3, 261-271.

Examples

glasses <- na.omit(glasses[,-1])
n <- nrow(glasses)
p <- ncol(glasses)
col <- rep("black",n)
col[glasses[,1] == 2] <- "red"
col[glasses[,1] == 3] <- "green"
lab <- rep("M",n)
lab[glasses[,1] == 1] <- "V"
lab[glasses[,1] == 2] <- "R"
lab1 <- paste(lab,1:n,sep="")
pc <- princomp(glasses[,-1],cor=TRUE)
summary(pc)
plot(scale(pc$scores[,1]), scale(pc$scores[,2]), pch=20, xlab="PC1 (36)",
  ylab="PC2 (28)", main="Roman Venetian Glasses Data")
text(scale(pc$scores[,1]), scale(pc$scores[,2]), labels=lab1, cex=0.6,
  pos=3, col=col)
abline(h=0, v=0, lty="dashed", col="grey")
plot(scale(pc$scores[,1]), scale(pc$scores[,3]), pch=20, xlab="PC1 (36)",
  ylab="PC3 (11)", main="Roman Venetian Glasses Data")
text(scale(pc$scores[,1]), scale(pc$scores[,3]), labels=lab1, cex=0.6,
  pos=3, col=col)
abline(h=0, v=0, lty="dashed", col="grey")
plot(scale(pc$scores[,2]), scale(pc$scores[,3]), pch=20, xlab="PC2 (28)",
  ylab="PC3 (11)", main="Roman Venetian Glasses Data")
text(scale(pc$scores[,2]), scale(pc$scores[,3]), labels=lab1, cex=0.6,
  pos=3, col=col)
abline(h=0, v=0, lty="dashed", col="grey")

set.seed(1234)
err1 <- rnorm(n,0,sd(glasses[,2])/100)
err2 <- rnorm(n,0,sd(glasses[,3])/100)
err3 <- rnorm(n,0,sd(glasses[,4])/100)
err4 <- rnorm(n,0,sd(glasses[,5])/100)
err5 <- rnorm(n,0,sd(glasses[,6])/100)
err6 <- rnorm(n,0,sd(glasses[,7])/100)
err7 <- rnorm(n,0,sd(glasses[,8])/100)
err8 <- rnorm(n,0,sd(glasses[,9])/100)
err9 <- rnorm(n,0,sd(glasses[,10])/100)
err10 <- rnorm(n,0,sd(glasses[,11])/100)
err11 <- rnorm(n,0,sd(glasses[,12])/100)
err12 <- rnorm(n,0,sd(glasses[,13])/100)
glasses <- glasses[,-1] + data.frame(err1,err2,err3,err4,err5,err6,err7,
  err8,err9, err10,err11,err12)

tau <- quantile.localdepth(glasses, probs=c(0.1, 0.9), method='mahalanobis')
gla10 <- localdepth(glasses, tau=tau[1], method='mahalanobis')
gla90 <- localdepth(glasses, tau=tau[2], method='mahalanobis')

plot(gla10)
abline(0, 1, lty=2)
plot(gla90)
abline(0, 1, lty=2)