Extra Coordinate Systems, 'Geoms', Statistical Transformations, Scales and Fonts for 'ggplot2'
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GeomEncircle <- ggproto("GeomEncircle", Geom,
required_aes = c("x", "y"),
default_aes = aes(colour = "black",
linetype=1,
size=1,
s_shape=0.5, ## corresponds to default shape in xspline of -0.5
s_open=FALSE,
expand=0.05,
spread=0.1),
draw_key = draw_key_point,
draw_group = function(data, panel_scales, coord) {
coords <- coord$transform(data, panel_scales)
first_row <- coords[1, , drop = FALSE]
rownames(first_row) <- NULL ## prevent warning later
m <- lapply(coords[,c("x","y")],mean,na.rm=TRUE)
ch <- grDevices::chull(coords[c("x","y")])
mkcoords <- function(x,y) {
data.frame(x,y,first_row[!names(first_row) %in% c("x","y")])
}
coords <- coords[ch,]
## FIXME: using grid:: a lot. importFrom instead?
## convert from lengths to physical units, for computing *directions*
cc <- function(x,dir="x")
grid::convertUnit(grid::unit(x,"native"),"mm",typeFrom="dimension",
axisFrom=dir,valueOnly=TRUE)
## convert back to native (e.g. native + snpc offset)
cc_inv <- function(x,dir="x")
grid::convertUnit(x,"native",typeFrom="location",
axisFrom=dir,valueOnly=TRUE)
cc_comb <- function(x1,x2,dir="x")
cc_inv(unit(x1,"native")+unit(x2,"snpc"),dir=dir)
## find normalized vector: d1 and d2 have $x, $y elements
normFun <- function(d1,d2) {
dx <- cc(d1$x-d2$x)
dy <- cc(d1$y-d2$y)
r <- sqrt(dx*dx+dy*dy)
list(x=dx/r,y=dy/r)
}
if (nrow(coords)==1) {
## only one point: make a diamond by spreading points vertically
## and horizontally
coords <- with(coords,
mkcoords(
c(x,x+spread,x,x-spread),
c(y+spread,y,y-spread,y)))
} else if (nrow(coords)==2) {
## only two points: make a diamond by spreading points perpendicularly
rot <- matrix(c(0,1,-1,0),2)
dd <- c(rot %*% unlist(normFun(coords[1,],coords[2,])))*
coords$spread
coords <- with(coords, {
## figure out rotated values, then convert *back* to native units
## already in scaled units, so ignore?
x <- c(x[1],
m$x+dd[1], ## cc_comb(m$x,dd[1]),
x[2],
m$x-dd[1]) ## cc_comb(m$x,-dd[1]))
y <- c(y[1],
m$y+dd[2], ## cc_comb(m$y,dd[2],"y"),
y[2],
m$y-dd[2]) ## cc_comb(m$y,-dd[2],"y"))
mkcoords(x,y)
})
}
disp <- normFun(coords,m)
grid::xsplineGrob(
with(coords,unit(x,"npc")+disp$x*unit(expand,"snpc")),
with(coords,unit(y,"npc")+disp$y*unit(expand,"snpc")),
## coords$x,
## coords$y,
shape = coords$s_shape-1, ## kluge!
open = first_row$s_open,
gp = with(first_row,
grid::gpar(col = colour, lty=linetype))
)
}
)
if (FALSE) {
library("grid")
library("gridBase")
coords <- data.frame(x=c(1,1),y=c(1,2)*100,spread=c(0.1,0.1))
plot(y~x,data=d,xlim=c(0,3),ylim=c(0,300))
vps <- baseViewports()
pushViewport(vps$inner)
pushViewport(vps$figure)
pushViewport(vps$plot)
## check that we're in the right place
m <- as.list(colMeans(coords))
grid.points(m$x,m$y,gp=gpar(col="red"))
cc <- function(x,dir="x")
grid::convertUnit(grid::unit(x,"native"),"mm",typeFrom="dimension",
axisFrom=dir,valueOnly=TRUE)
cc_inv <- function(x,dir="x")
grid::convertUnit(x,"native",typeFrom="location",
axisFrom=dir,valueOnly=TRUE)
cc_comb <- function(x1,x2,dir="x")
cc_inv(unit(x1,"native")+unit(x2,"snpc"),dir=dir)
## find normalized vector: d1 and d2 have $x, $y elements
normFun <- function(d1,d2) {
dx <- cc(d1$x-d2$x)
dy <- cc(d1$y-d2$y)
r <- sqrt(dx*dx+dy*dy)
list(x=dx/r,y=dy/r)
}
dd <- c(rot %*% unlist(normFun(coords[1,],coords[2,])))*
coords$spread
z <- with(coords, {
## figure out rotated values, then convert *back* to native units
x <- c(x[1],
cc_comb(m$x,dd[1]),
x[2],
cc_comb(m$x,-dd[1]))
y <- c(y[1],
cc_comb(m$y,dd[2],"y"),
y[2],
cc_comb(m$y,-dd[2],"y"))
list(x=x,y=y)
})
with(z,grid.points(x,y,gp=gpar(col="blue")))
print(grid::convertWidth(unit(1,'npc'),'native'))
print(grid::convertHeight(unit(1,'npc'),'native'))
}
##' encircle
##'
##' @title encircle
##' @param mapping mapping
##' @param data data
##' @param stat stat
##' @param position position
##' @param na.rm na.rm
##' @param show.legend show.legend
##' @param inherit.aes inherit.aes
##' @param ... dots
##' @return adds a circle around the specified points
##' @author Ben Bolker
##' @export
##' @examples
##' d <- data.frame(x=c(1,1,2),y=c(1,2,2)*100)
##' (g0 <- ggplot(d,aes(x,y))+geom_point()+
##' geom_encircle(s_shape=1,expand=0)+
##' geom_encircle(s_shape=1,expand=0.1,colour="red")+
##' scale_x_continuous(expand=c(0.5,1))+
##' scale_y_continuous(expand=c(0.5,1))+
##' geom_encircle(s_shape=0.5,expand=0.1,colour="purple"))
##' g0 + geom_encircle(data=subset(d,x==1),colour="blue",spread=0.02)+
##' geom_encircle(data=subset(d,x==2),colour="cyan",spread=0.04)
##'
##' g0 <- ggplot(mpg, aes(displ, hwy)) + geom_point()
##' (g1 <- g0 + geom_encircle(data=subset(mpg,hwy>40)))
##' ss <- subset(mpg,hwy>31 & displ<2)
##' g1 + geom_point(data=ss,colour="blue")+
##' geom_encircle(data=ss,colour="blue",s_shape=0.9,
##' expand=0.07)
geom_encircle <- function(mapping = NULL, data = NULL, stat = "identity",
position = "identity", na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, ...) {
layer(
geom = GeomEncircle, mapping = mapping, data = data, stat = stat,
position = position, show.legend = show.legend, inherit.aes = inherit.aes,
params = list(na.rm = na.rm, ...)
)
}