anno_empty {ComplexHeatmap} | R Documentation

## Empty Annotation

### Description

Empty Annotation

### Usage

    anno_empty(which = c("column", "row"), border = TRUE, zoom = FALSE,
        width = NULL, height = NULL)

### Arguments

`which` | Whether it is a column annotation or a row annotation?
`border` | Whether draw borders of the annotation region?
`zoom` | If it is true and when the heatmap is split, the empty annotation slices will have equal height or width, and you can see the correspondance between the annotation slices and the original heatmap slices.
`width` | Width of the annotation. The value should be an absolute unit. Width is not allowed to be set for column annotation.
`height` | Height of the annotation. The value should be an absolute unit. Height is not allowed to be set for row annotation.

### Details

It creates an empty annotation and holds space, later users can add graphics by `decorate_annotation`. This function is useful when users have difficulty to implement `AnnotationFunction` object.

In following example, an empty annotation is first created and later points are added:

    	m = matrix(rnorm(100), 10)
    	ht = Heatmap(m, top_annotation = HeatmapAnnotation(pt = anno_empty()))
    	ht = draw(ht)
    	co = column_order(ht)[[1]]
    	pt_value = 1:10
    	decorate_annotation("pt", {
    		pushViewport(viewport(xscale = c(0.5, ncol(mat)+0.5), yscale = range(pt_value)))
    		grid.points(seq_len(ncol(mat)), pt_value[co], pch = 16, default.units = "native")
    		grid.yaxis()
    		popViewport()
    	})

And it is similar as using `anno_points`:

    	Heatmap(m, top_annotation = HeatmapAnnotation(pt = anno_points(pt_value)))

### Value

An annotation function which can be used in `HeatmapAnnotation`.

### See Also

https://jokergoo.github.io/ComplexHeatmap-reference/book/heatmap-annotations.html#empty-annotation

### Examples

    anno = anno_empty()
    draw(anno, test = "anno_empty")
    anno = anno_empty(border = FALSE)
    draw(anno, test = "anno_empty without border")

[Package ComplexHeatmap version 2.3.4 Index]