ggpp (version 0.5.1)

compute_npcx: Compute npc coordinates

Description

Convert character-encoded positions to npc units and shift positions to avoid overlaps when grouping is active. If numeric, validate npc values.

Usage

compute_npcx(x, group = 1L, h.step = 0.1, margin.npc = 0.05, each.len = 1)
compute_npcy(y, group = 1L, v.step = 0.1, margin.npc = 0.05, each.len = 1)

Value

A numeric vector with values in the range [0..1] representing npc coordinates.

Arguments

x

numeric or if character, one of "right", "left", "centre", "center" or "middle".

group

integer vector, ggplot's group id. Used to shift coordinates to avoid overlaps.

h.step, v.step

numeric [0..1] The step size for shifting coordinates in npc units. Usually << 1.

margin.npc

numeric [0..1] The margin added towards the nearest plotting area edge when converting character coordinates into npc. Usually << 1.

each.len

integer The number of steps per group.

y

numeric or if character, one of "top", "bottom", "centre", "center" or "middle".

Details

These functions use NPC (normalized plot coordinates) instead of data coordinates. They translate named positions into numeric values in [0..1] and they can also shift the position according to the group, e.g., for each increase in the group number displace the position inwards or outwards, by a user-supplied distance. They make it possible to set automatically set default positions for grouped text labels.

Out of bounds numeric values are constrained to [0..1]. Unrecognized character values are silently converted into NA_integer_.

Examples

compute_npcx("right")
compute_npcx(c("left", "right"))
compute_npcy("bottom")
compute_npcy("bottom", group = 1L:3L)
compute_npcy("bottom", group = 2L)
compute_npcx(0.5)
compute_npcx(1)