Is it possible to add custom shapes ( from png) to ggplot legend? - r

I was wondering whether it is possible to add shapes to the legend for ggimage(). I found similar questions, but they either have 1) same picture with a different color in legend, or 2) same picture different colors. I used this link to add images to the legend that have color, but i can't figure out how to edit it so that image will be different. I tried this, but I am not advance enough to adjust the code to fit my case
d <- data.frame(x = rnorm(10),
y = rnorm(10),
image = sample(c("https://www.r-project.org/logo/Rlogo.png",
"https://jeroenooms.github.io/images/frink.png"),
size=10, replace = TRUE)
)
ggplot(d, aes(x, y)) + geom_image(aes(image=image, color=image), size=.05)

Solved by ussing ggdraw:
p2 os the ggplot() object where I ploted images in row (coordinates x=2, y = c(1,2) ) and added text (coordinates x=2.5, y=c(1,2))
ggdraw() +
draw_plot(p1) +
draw_plot(p2, x = 0.55, y = 0.6)
And then I just play around with the position of p2 as well as added xlim and ylim to p2 to make text and image together

Related

Insert rectangle outside of ggplot to visualize plot segments

I hope you can help me. I have the idea of visualizing segments within a plot with a rectangle that can be placed next to the y or x-axis which means that it would be outside of the plot area. It should look similar as in the image below:
I tried to reach the mentioned output by trying two different approaches:
I created two viewports with the grid package and put the plot in one viewport that I placed at the bottom and one viewport on top of that. The big problem here is that I need the coordinates from where the grey background panel of the ggplot starts so I can place the top viewport exactly there, so that the segments conincide with the x-axis length. My code looked like following:
container_viewport <- viewport(x=0,y=0,height=1,width=1,just = c("left","bottom"))
pushViewport(container_viewport)
grid.draw(rectGrob())
popViewport()
section_viewport <- viewport(x=0.055,y=0.99,height=0.085,width=0.935,just=c("left","top"))
pushViewport(section_viewport)
plot_obj <- ggplot_build(testplot)
plot_data <- plot_obj$data[[1]]
grid.draw(rectGrob(gp = gpar(col = "red")))
popViewport()
plot_viewport <- viewport(x=0,y=0,height=0.9,width=1,just=c("left","bottom"))
pushViewport(plot_viewport)
grid.draw(ggplotGrob(testplot))
popViewport()
This looks fine but I had to hardcode the coordinates of the viewport at the top.
I used grid.arrange() to arrange to stack the plots vertically (instead of a grob for the rectangle like in the other approach I create a ggplot instead for that). Here, basically the same problem exists, since I somehow need to put the plot representing the rectangle at the top in the right position on the x-axis. My code looked like following:
p1 <- plot_data %>%
ggplot()+
geom_rect(aes(xmin=-Inf,xmax=Inf,ymin=-Inf,ymax=Inf))
p2 <- testplot
test_plot <- grid.arrange(p1,p2,heights=c(1,10))
This approach does not work that good.
Since I would like to create a solution that can be applied generally, trial and error with the coordinates of the viewport is no option since the length of the y-axis label or tick labels can vary and therefore the length and coordinates of the background panel. When this step is done the segmentation of the rectangle should be no problem anymore.
Maybe this is just not possible but if then I would appreciate any help.
Thank you!
I would probably use patchwork here. Let's start by replicating your plot:
library(ggplot2)
library(patchwork)
p <- ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
geom_point(color = "red") +
labs(x = "test", y = "test")
p
That looks very similar. Now we define (in our own co-ordinates) where we want the section split to occur on the x axis.
section_split <- 5.25
Using just this number, we add rectangles and text annotations that cover a copy of our original plot, and remove its axis annotations using theme_void:
p2 <- p +
annotate("rect", xmin = c(-Inf, section_split), ymin = c(-Inf, -Inf),
xmax = c(section_split, Inf), ymax = c(Inf, Inf),
fill = c("#00a2e8", "#ff7f27")) +
annotate("text", label = c("Section A", "Section B"), size = 6,
y = rep(mean(layer_scales(p)$y$range$range), 2),
x = c((min(layer_scales(p)$x$range$range) + section_split)/2,
(max(layer_scales(p)$x$range$range) + section_split)/2)) +
theme_void()
Now we just draw this second plot above our first, adjusting the relative heights to about 1:10
p2/p + plot_layout(heights = c(1, 10))
The benefit of doing it this way is that, since we copied the original plot, the positional mapping of the x axis is identical between the two plots, and patchwork will automatically line up the panels.
Created on 2023-02-04 with reprex v2.0.2

Create standard color scale for several graphs

I am trying to create a custom color scale for several graphs. I would like it to be a standard color scheme so that the two graphs can be compared. The data for the first graph has a much smaller range (its maximum is just a bit above 3) while the other one goes to 9. Therefore, I need colors to match numbers 4-9 but do not want them to appear in the first graph. However, they always do and I do not understand why.
Here is the data for the first graph:
df <- data.frame(
x = runif(100),
y = runif(100),
z1 = rnorm(100),
z2 = abs(rnorm(100))
)
And here is the graph, with the custom color scale. However, as you can see all the colors appear in the graph even though only the first 5 colors should show up.
ggplot(df, aes(x, y)) +
geom_point(aes(colour = z2))+scale_colour_gradientn(colours = c('springgreen1', 'springgreen4', 'yellowgreen','yellow2','lightsalmon','orange','orange3','orange4','navajowhite3','white'),breaks=c(0,1,2,3,4,5,6,7,8,9))
The limits term of scale_colour_gradientn can help here:
ggplot(df, aes(x, y)) +
geom_point(aes(colour = z2))+
scale_colour_gradientn(colours = c('springgreen1', 'springgreen4', 'yellowgreen','yellow2',
'lightsalmon','orange','orange3','orange4','navajowhite3','white'),
breaks=c(0,1,2,3,4,5,6,7,8,9),
limits = c(0,9)) +
theme(legend.key.height = unit(1.5, "cm"))

ggplot: place image in corner of panel

I'm trying to find a way to insert an image into the corner of a ggplot panel, without specifying the coordinates manually each time.
In this instance, I'm attempting to place a graphic in the top right.
library(magick)
library(ggplot2)
library(datasets)
homer <- magick::image_read("http://icons.iconarchive.com/icons/jonathan-rey/simpsons/128/Homer-Simpson-04-Happy-icon.png")
g <- ggplot(mpg, aes(class)) +
geom_bar() +
labs(
title = "Count of Auto by Class",
subtitle = "Text to Create More Space")
g + annotation_custom(rasterGrob(homer, interpolate = TRUE),
xmax = Inf, ymax = Inf) +
coord_cartesian(clip = "off")
I have found some examples that come close to solving this:
Inserting an image to ggplot outside the chart area
Corner Labels in ggplot2
But neither quite get there. Specifying the exact location at which to place the image seems to require quite a bit of trial-and-error on each plot created, especially when x is categorical.
I would also like to maintain the size of my original image; the code I've used above seems to stretch it across the plot.
Thanks in advance...much appreciated.
try this
library(grid)
a <- rasterGrob(homer, interpolate = TRUE,
width=unit(1,'cm'),
x = unit(1,"npc"), y = unit(1,"npc"),
hjust = 1, vjust=1)
g + annotation_custom(grob = a)

Keep all plot components same size in ggplot2 between two plots

I would like two separate plots. I am using them in different frames of a beamer presentation and I will add one line to the other (eventually, not in example below). Thus I do not want the presentation to "skip" ("jump" ?) from one slide to the next slide. I would like it to look like the line is being added naturally. The below code I believe shows the problem. It is subtle, but not how the plot area of the second plot is slightly larger than of the first plot. This happens because of the y axis label.
library(ggplot2)
dfr1 <- data.frame(
time = 1:10,
value = runif(10)
)
dfr2 <- data.frame(
time = 1:10,
value = runif(10, 1000, 1001)
)
p1 <- ggplot(dfr1, aes(time, value)) + geom_line() + scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + ylab(expression(hat(z)==hat(gamma)[1]*time+hat(gamma)[4]*time^2))
print(p1)
dev.new()
p2 <- ggplot(dfr2, aes(time, value)) + geom_line() + scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + ylab(".")
print(p2)
I would prefer to not have a hackish solution such as setting the size of the axis label manually or adding spaces on the x-axis (see one reference below), because I will use this technique in several settings and the labels can change at any time (I like reproducibility so want a flexible solution).
I'm searched a lot and have found the following:
Specifying ggplot2 panel width
How can I make consistent-width plots in ggplot (with legends)?
https://groups.google.com/forum/#!topic/ggplot2/2MNoYtX8EEY
How can I add variable size y-axis labels in R with ggplot2 without changing the plot width?
They do not work for me, mainly because I need separate plots, so it is not a matter of aligning them virtically on one combined plot as in some of the above solutions.
haven't tried, but this might work,
gl <- lapply(list(p1,p2), ggplotGrob)
library(grid)
widths <- do.call(unit.pmax, lapply(gl, "[[", "widths"))
heights <- do.call(unit.pmax, lapply(gl, "[[", "heights"))
lg <- lapply(gl, function(g) {g$widths <- widths; g$heights <- heights; g})
grid.newpage()
grid.draw(lg[[1]])
grid.newpage()
grid.draw(lg[[2]])
How about using this for p2:
p2 <- ggplot(dfr2, aes(time, value)) + geom_line() +
scale_y_continuous(breaks = NULL) +
scale_x_continuous(breaks = NULL) +
ylab(expression(hat(z)==hat(gamma)[1]*time+hat(gamma)[4]*time^2)) +
theme(axis.title.y=element_text(color=NA))
This has the same label as p1, but the color is NA so it doesn't display. You could also use color="white".

ggplot2 annotate layer position in R

In my plot I have both legends and text annotations. For legends, I can specify
legend.justification=c(1,0), legend.position=c(1,0)
to locate the position relative to the plotting region (e.g. topright, bottomleft). However, when I put an annotate layer (http://docs.ggplot2.org/0.9.3.1/annotate.html), it seems that I can only specify the coordinates of the text
annotate("text", x = 8e-7, y = 1e-5, label=data.note, size = 5)
instead of the position of the plotting region (I want to put the text in the bottomleft corner). The length of the text (label) may vary for different plots. Is there a way to achieve this? Thanks!
You can use the fact that -Inf and Inf will get mapped to the extremes of the position scales without extending them to place it in the bottom left corner. hjust and vjust are needed to make the reference point the lower left corner of your text. [using jlhoward's mock data.]
set.seed(1)
df <- data.frame(x=rnorm(100),y=rnorm(100))
ggplot(df, aes(x,y)) +geom_point()+
annotate("text",x=-Inf,y=-Inf,hjust=0,vjust=0,label="Text annotation")
Is this what you're looking for??
set.seed(1)
df <- data.frame(x=rnorm(100),y=rnorm(100))
ggplot(df, aes(x,y)) +geom_point()+
annotate("text",x=min(df$x),y=min(df$y),hjust=.2,label="Text annotation")
There will probably be a bit of experimentation with hjust=... needed to get this exactly at the bottom left.
The "Inf" solution has problems when you want multi-line text. In addition, it there is no margin between the text and the panel edge, which is ugly. The other solution requires explicit mention of the data which is not good either.
The desired effect can be achieved nicely with annotation_custom (or in my example, the proto Geom directly). You have configurable margin, text and box justification.
The added bonus in the following code is that you can specify which facet to annotate with something like facets=data.frame(cat1='blue', cat2='tall').
library("ggplot2")
annotate_textp <- function(label, x, y, facets=NULL, hjust=0, vjust=0, color='black', alpha=NA,
family=thm$text$family, size=thm$text$size, fontface=1, lineheight=1.0,
box_just=ifelse(c(x,y)<0.5,0,1), margin=unit(size/2, 'pt'), thm=theme_get()) {
x <- scales::squish_infinite(x)
y <- scales::squish_infinite(y)
data <- if (is.null(facets)) data.frame(x=NA) else data.frame(x=NA, facets)
tg <- grid::textGrob(
label, x=0, y=0, hjust=hjust, vjust=vjust,
gp=grid::gpar(col=alpha(color, alpha), fontsize=size, fontfamily=family, fontface=fontface, lineheight=lineheight)
)
ts <- grid::unit.c(grid::grobWidth(tg), grid::grobHeight(tg))
vp <- grid::viewport(x=x, y=y, width=ts[1], height=ts[2], just=box_just)
tg <- grid::editGrob(tg, x=ts[1]*hjust, y=ts[2]*vjust, vp=vp)
inner <- grid::grobTree(tg, vp=grid::viewport(width=unit(1, 'npc')-margin*2, height=unit(1, 'npc')-margin*2))
layer(
data = NULL,
stat = StatIdentity,
position = PositionIdentity,
geom = GeomCustomAnn,
inherit.aes = TRUE,
params = list(
grob=grid::grobTree(inner),
xmin=-Inf,
xmax=Inf,
ymin=-Inf,
ymax=Inf
)
)
}
qplot(1:10,1:10) + annotate_text2('some long text\nx = 1', x=0.5, y=0.5, hjust=1)

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