ggbplot {Correlplot}

Create a biplot with ggplot2

Description

Function ggbiplot creates a biplot of a matrix with ggplot2 graphics.

Usage

ggbplot(A, B, main = "", circle = TRUE, xlab = "", ylab = "", main.size = 8,
xlim = c(-1, 1), ylim = c(-1, 1), rowcolor = "red", rowch = 1, colcolor = "blue",
colch = 1, rowarrow = FALSE, colarrow = TRUE)

Arguments

A

A dataframe with coordinates and names for the biplot row markers

B

A dataframe with coordinates and names for the biplot column markers

main

A title for the biplot

circle

Draw a unit circle (circle=TRUE) or not (circle=FALSE)

xlab

The label for the x axis

ylab

The label for the y axis

main.size

Size of the main title

xlim

Limits for the horizontal axis

ylim

Limits for the vertical axis

rowcolor

Color used for the row markers

rowch

Symbol used for the row markers

colcolor

Color used for the column markers

colch

Symbol used for the column markers

rowarrow

Draw arrows from the origin to the row markers (rowarrow=TRUE) or not

colarrow

Draw arrows from the origin to the column markers (colarrow=TRUE) or not

Details

Dataframes A and B must consists of three columns labeled "PA1", "PA2" (coordinates of the first and second principal axis) and a column "strings" with the labels for the coordinates.

Dataframe B is optional. If it is not specified, a biplot with a single set of markers is constructed, for which the row settings must be specified.

Value

A ggplot2 object

Author(s)

Jan Graffelman ([e-mail])

References

Graffelman, J. and De Leeuw, J. (2023) On the visualisation of the correlation matrix. Available online. doi:10.48550/arXiv.2211.13150

See Also

bplot,ggtally,biplot

Examples

data("HeartAttack")
X <- as.matrix(HeartAttack[,1:7])
n <- nrow(X)
Xt <- scale(X)/sqrt(n-1)
res.svd <- svd(Xt)
Fs <- sqrt(n)*res.svd$u # standardized principal components
Gp <- crossprod(t(res.svd$v),diag(res.svd$d)) # biplot coordinates for variables
rows.df <- data.frame(Fs[,1:2],as.character(1:n))
colnames(rows.df) <- c("PA1","PA2","strings")
cols.df <- data.frame(Gp[,1:2],colnames(X))
colnames(cols.df) <- c("PA1","PA2","strings")
ggbplot(rows.df,cols.df,xlab="PA1",ylab="PA2",main="PCA")