As per my comment in Chase's answer, you can remove a lot of this stuff using element_blank
:
dat <- data.frame(x=runif(10),y=runif(10))
p <- ggplot(dat, aes(x=x, y=y)) +
geom_point() +
scale_x_continuous(expand=c(0,0)) +
scale_y_continuous(expand=c(0,0))
p + theme(axis.line=element_blank(),axis.text.x=element_blank(),
axis.text.y=element_blank(),axis.ticks=element_blank(),
axis.title.x=element_blank(),
axis.title.y=element_blank(),legend.position="none",
panel.background=element_blank(),panel.border=element_blank(),panel.grid.major=element_blank(),
panel.grid.minor=element_blank(),plot.background=element_blank())
It looks like there's still a small margin around the edge of the resulting .png when I save this. Perhaps someone else knows how to remove even that component.
(Historical note: Since ggplot2 version 0.9.2, opts
has been deprecated. Instead use theme()
and replace theme_blank()
with element_blank()
.)
Since @Etienne asked how to do this without melting the data (which in general is the preferred method, but I recognize there may be some cases where that is not possible), I present the following alternative.
Start with a subset of the original data:
datos <-
structure(list(fecha = structure(c(1317452400, 1317538800, 1317625200,
1317711600, 1317798000, 1317884400, 1317970800, 1318057200, 1318143600,
1318230000, 1318316400, 1318402800, 1318489200, 1318575600, 1318662000,
1318748400, 1318834800, 1318921200, 1319007600, 1319094000), class = c("POSIXct",
"POSIXt"), tzone = ""), TempMax = c(26.58, 27.78, 27.9, 27.44,
30.9, 30.44, 27.57, 25.71, 25.98, 26.84, 33.58, 30.7, 31.3, 27.18,
26.58, 26.18, 25.19, 24.19, 27.65, 23.92), TempMedia = c(22.88,
22.87, 22.41, 21.63, 22.43, 22.29, 21.89, 20.52, 19.71, 20.73,
23.51, 23.13, 22.95, 21.95, 21.91, 20.72, 20.45, 19.42, 19.97,
19.61), TempMin = c(19.34, 19.14, 18.34, 17.49, 16.75, 16.75,
16.88, 16.82, 14.82, 16.01, 16.88, 17.55, 16.75, 17.22, 19.01,
16.95, 17.55, 15.21, 14.22, 16.42)), .Names = c("fecha", "TempMax",
"TempMedia", "TempMin"), row.names = c(NA, 20L), class = "data.frame")
You can get the desired effect by (and this also cleans up the original plotting code):
ggplot(data = datos, aes(x = fecha)) +
geom_line(aes(y = TempMax, colour = "TempMax")) +
geom_line(aes(y = TempMedia, colour = "TempMedia")) +
geom_line(aes(y = TempMin, colour = "TempMin")) +
scale_colour_manual("",
breaks = c("TempMax", "TempMedia", "TempMin"),
values = c("red", "green", "blue")) +
xlab(" ") +
scale_y_continuous("Temperatura (C)", limits = c(-10,40)) +
labs(title="TITULO")
The idea is that each line is given a color by mapping the colour
aesthetic to a constant string. Choosing the string which is what you want to appear in the legend is the easiest. The fact that in this case it is the same as the name of the y
variable being plotted is not significant; it could be any set of strings. It is very important that this is inside the aes
call; you are creating a mapping to this "variable".
scale_colour_manual
can now map these strings to the appropriate colors. The result is
In some cases, the mapping between the levels and colors needs to be made explicit by naming the values in the manual scale (thanks to @DaveRGP for pointing this out):
ggplot(data = datos, aes(x = fecha)) +
geom_line(aes(y = TempMax, colour = "TempMax")) +
geom_line(aes(y = TempMedia, colour = "TempMedia")) +
geom_line(aes(y = TempMin, colour = "TempMin")) +
scale_colour_manual("",
values = c("TempMedia"="green", "TempMax"="red",
"TempMin"="blue")) +
xlab(" ") +
scale_y_continuous("Temperatura (C)", limits = c(-10,40)) +
labs(title="TITULO")
(giving the same figure as before). With named values, the breaks can be used to set the order in the legend and any order can be used in the values.
ggplot(data = datos, aes(x = fecha)) +
geom_line(aes(y = TempMax, colour = "TempMax")) +
geom_line(aes(y = TempMedia, colour = "TempMedia")) +
geom_line(aes(y = TempMin, colour = "TempMin")) +
scale_colour_manual("",
breaks = c("TempMedia", "TempMax", "TempMin"),
values = c("TempMedia"="green", "TempMax"="red",
"TempMin"="blue")) +
xlab(" ") +
scale_y_continuous("Temperatura (C)", limits = c(-10,40)) +
labs(title="TITULO")
Best Answer
The following is an extension to an answer I wrote for a previous question about utilising the space from empty facet panels, but I think it's sufficiently different to warrant its own space.
Essentially, I wrote a function that takes a ggplot/grob object converted by
ggplotGrob()
, converts it to grob if it isn't one, and digs into the underlying grobs to move the legend grob into the cells that correspond to the empty space.Function:
Result:
Nicer looking result if we take advantage of the empty space's direction to arrange the legend horizontally:
Some other examples: