annotation: Annotation class and class functions

Description

An annotation describes a DNA segment. It has labels attached to positions. Each label can be attached to a single position or to a range.

Usage

annotation(x1, x2 = NA, text, rot = 0, col = "black")
as.annotation(df, x2 = NA, rot = 0, col = "black")
is.annotation(annotation)

Arguments

Numeric. A vector giving the first or only position of the label. Mandatory.

Numeric. A vector of the same length as x1. If a row (or the whole column is NA, then the annotation(s) will be attached to x0. Else, the annotation will be attached to the range between both positions.

text

Character of the same length as x0. Gives the text of the labels. Mandatory.

rot

Numeric of the same length as x0. Gives the rotation, in degrees, of the labels. 0 by default.

col

Vector of the same length as x0. The color of the labels. black by default.

A data frame to convert to an annotation object. Should have at least columns x1 and text.

annotation

An object to test.

Value

annotation and as.annotation return an annotation object. is.annotation returns a logical.

Details

An annotation object is a data frame with columns x0, x1, text, col and rot. They give, respectively, the first (or only) position, eventually the second position, the text, the color and the rotation of the annotation. When plotted with plot_gene_map, it will add an annotation row on top of the first dna_seg. Labels for which only one position is given will be centered on that position. Labels for which two positions are given are linked by an horizontal square bracket and the label is plotted in the middle of the positions.

Examples

Run this code

## loading data
data(three_genes)

## Calculating middle positions
mid_pos <- middle(dna_segs[[1]])

# Create first annotation
annot1 <- annotation(x1=mid_pos, text=dna_segs[[1]]$name)
plot_gene_map(dna_segs=dna_segs, comparisons=comparisons, annotations=annot1)

## Exploring options
annot2 <- annotation(x1=c(mid_pos[1], dna_segs[[1]]$end[2]),
                     x2=c(NA, dna_segs[[1]]$end[3]),
                     text=c(dna_segs[[1]]$name[1], "region1"),
                     rot=c(30, 0), col=c("grey", "black"))
plot_gene_map(dna_segs=dna_segs, comparisons=comparisons,
              annotations=annot2, annotation_height=1.3)

## Annotations on all the segments
annots <- lapply(dna_segs, function(x){
  mid <- middle(x)
  annot <- annotation(x1=mid, text=x$name, rot=30)
})
plot_gene_map(dna_segs=dna_segs, comparisons=comparisons,
              annotations=annots, annotation_height=1.8, annotation_cex=1)