annotation: Annotation class and class functions
In genoPlotR: Plot Publication-Grade Gene and Genome Maps

Description Usage Arguments Details Value Author(s) See Also Examples

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.

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

`x1`	Numeric. A vector giving the first or only position of the label. Mandatory.
`x2`	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. `NA` by default.
`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.
`df`	A data frame to convert to an annotation object. Should have at least columns `x1` and `text`.
`annotation`	An object to test.

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.

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

Lionel Guy

plot_gene_map, middle.

## 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)

##
## Using a bigger dataset from a 4-genome comparison
##
data(barto)
## Adding a tree
tree <- newick2phylog("(BB:2.5,(BG:1.8,(BH:1,BQ:0.8):1.9):3);")
## Showing several subsegments
xlims2 <- list(c(1445000, 1415000, 1380000, 1412000),
               c(  10000,   45000,   50000,   83000, 90000, 120000),
               c(  15000,   36000,   90000,  120000, 74000,  98000),
               c(   5000,    82000))
## Adding annotations for all genomes, allow segments to be placed out
## of the longest segment
annots <- lapply(barto$dna_segs, function(x){
  mid <- middle(x)
  annot <- annotation(x1=mid, text=x$name, rot=30)
  # removing gene names starting with "B" and keeping 1 in 4
  idx <- grep("^[^B]", annot$text, perl=TRUE)
  annot[idx[idx %% 4 == 0],] 
})
plot_gene_map(barto$dna_segs, barto$comparisons, tree=tree,
              annotations=annots,
              xlims=xlims2,
              limit_to_longest_dna_seg=FALSE,
              dna_seg_scale=TRUE)