strwidth2xlim {broman}

Calculate horizontal limit in user coordinates for adding labels

Description

Calculates the x-axis limits when adding (long) labels to a plot

Usage

strwidth2xlim(x, xstring, pos = 4, offset = 0.5, ...)

Arguments

x

numeric vector of horizontal coordinates

xstring

character vector, specifying text to be written

pos

position specifier for text; values of 1, 2, 3, and 4, respectively, indicate positions below, to the left of, above, and to the right of the coordinates

offset

offset of the label from the coordinate in fractions of a character width

...

additional text parameters from par, such as cex

Details

See text for details on pos and offset.

Value

Minimum and maximum x-axis limits for adding horizontal text

Author(s)

Aimee Teo Broman

See Also

graphics::text()

Examples

x <- runif(15,-1,1)*10
xlabs <- sapply(sample(1:20,15,replace=TRUE),
         function(a) paste(LETTERS[1:a], collapse=""))
## Labels to the left ##
xlims <- strwidth2xlim(x,xlabs,pos=2)
plot(x,1:length(x),xlim=xlims)
text(x,1:length(x),xlabs,pos=2)
## Labels to the right ##
xlims <- strwidth2xlim(x,xlabs,pos=4,cex=0.7)
plot(x,1:length(x),xlim=xlims)
text(x,1:length(x),xlabs,pos=4,cex=0.7)