add_axes_labels: Add labels to an axis at given positions

In markheckmann/dissertation: Functions used in dissertation

Description

Add labels to an axis at given positions

Usage

add_axes_labels(v, U, labels, i = 1:nrow(U), ortho = FALSE, below = TRUE,
  line = 1, srt = NULL, ...)

Arguments

v	Direction vector of axis.
U	Points on axis in user coordinates
labels	Labels to place on axis.
i	Indexes of which labels to plot.
ortho	Labels orthogonal to axis? (default FALSE).
below	Should the label appear below the axis?
line	Number of lines label is placed below axis.
srt	A numerical value specifying (in degrees) how the text should be rotated.
...	Passed on to text to plot labels.

Details

Places value labels at given points and in direction given by vector. The labels are rotated automatically to be readable.

Examples

# generate data
set.seed(1)
v <- c(1,1)                                         # vector in direction of axis
X <- t(replicate(4, runif(1, -1, 1) * v))           # generate points on axis

## plot 1: add labels parallel to axis

plot(X, pch=16, asp=1, xlim=c(-1,1), ylim=c(-1,1))  
abline(h=0, v=0, col="grey")
abline(0, 1)    

# add point coords as labels
lbls <- apply(X, 1, function(x) paste(round(x,1), collapse=","))
add_axes_labels(v, X, lbls, cex=.7)


## plot 2: add labels perpendicular to axis / without rotation

plot(X, pch=16, asp=1, xlim=c(-1,1), ylim=c(-1,1))  
abline(h=0, v=0, col="grey")
abline(0, 1)  

# add projected values on vector as labels 
vn <- v / sum(v^2)^.5                               # normalize vector for projection             
lbls <- X %*% v                                     # project points on vector
add_axes_labels(v, X, round(lbls,1), cex=.7, 
                below=FALSE, col="blue", ortho=TRUE)
add_axes_labels(v, X, round(lbls, 1), cex=.7, srt=0, 
                line = .5, col="grey")

markheckmann/dissertation documentation built on May 21, 2019, 12:06 p.m.