I am trying to insert a logo in my plot using geom_image(). The original logo is available here:
https://www.itvoice.in/wp-content/uploads/2016/12/zebronics_footer_logo.png
and looks like this:
When I make a ggplot using the code below, I get this image where the logo is shrunk along the x axis.
When I used reprex to make this post, the resulting logo was shrunk along Y axis. Neither of them is the correct rendition. I can't figure out what's going on here. I tried to play around with various parameters such as size and asp but I can't reproduce the original logo correctly.
library(ggplot2)
library(ggimage)
df <- data.frame(imglink = "https://www.itvoice.in/wp-content/uploads/2016/12/zebronics_footer_logo.png",
x = 1,
y = 1)
ggplot(df, aes(x = x, y = y, image = imglink)) +
geom_image(size = 0.5) +
theme_bw()
Created on 2020-03-07 by the reprex package (v0.3.0)
This issue got resolved after I installed development versions of ggimage and ggplot2 and restarted RStudio.
Related
I have a number of plots using {ggplot2} and {ggiraph} that I have consolidated into a {flexdashboard}
Before attempting to display them with the dashboard, these plots displayed correctly on RStudio's viewer using the sizing option width = 0.7
However, they do not display on the dashboard (just a blank panel), and now produce a blank panel if run directly in RStudio. After some investigation it seems that some setting has changed and that the charts are not output because the size is inconsistent with the window.
If I change the width setting to 10 it displays correctly in the RStudio viewer which seems odd.
I have a small reprex here:
library(ggplot2)
library(ggiraph)
#dummy dataframe
df <- data.frame(
x = seq.Date(Sys.Date() - 30, Sys.Date() - 1, by = "days"),
y = runif(30, 0, 2)
)
p <- ggplot2::ggplot(df, (aes(x,y)))+
geom_point_interactive(aes(tooltip = x, data_id = x))
plot <- girafe(ggobj = p,
width =0.7)
print(plot)
This produces the following output:
However if I adjust width setting to 10
plot <- girafe(ggobj = p,
width =10)
print(plot)
I get the following:
This seems inconsistent with the documentation for {ggiraph}, is there some graphics setting that has been modified by {flexdashboard}? I've tried interactive (js) charts with {plotly} and {echarts4r} on {flexdashboard} output which don't show the same behaviour.
I'm using
RStudio 1.4.1103
R version 4.0.2
System: x86_64-apple-darwin17.0
I've been experimenting and it seems that I can control the output by using width_svg consistently.
I still don't know why there is an issue but I suspect some underlying graphics setting.
I build scatterplots using ggplot2 in R. I then want to save them as svg files with Cairo::CairoSVG. It seems to work fine except for the point size, which is enlarged in the resulting .svg file.
Here comes some example code:
library (ggplot2)
my_plot <- ggplot(mpg, aes(cty, hwy)) +
geom_point(size = 0.5)
x11 (width = 6, height = 6)
my_plot
Cairo::CairoSVG (file = "my_path",
width = 6, height = 6)
print (my_plot)
dev.off()
And this is what I get: on the right hand, the plot printed in R and on the left side the saved .svg-file opened in Inkscape. It looks fine except for the point size, which is a pity. Are there any ideas on how to get the right point-size? I tried different point sizes and also shapes, with similarly unmatched results.
Note that I seek to stick with Cairo::CairoSVG, beacuse in the final plots I wish to use custom fonts which are printed nicely with Cairo::CairoSVG. Any help is appreciated.
EDIT: I am working on a Windows machine.
Preliminary remark: when you pass width = 6, height = 6 in the Cairo::CairoSVG() parameters, you provide potentially different parameters (resolution and display) from the ones used in the RStudio plot panel.
To get the exact same image than the one rendered in the panel as well as using Cairo, you can use this alternative (dev.size('px') returns the dimensions of the current plot panel):
library (ggplot2)
my_plot <- ggplot(mpg, aes(cty, hwy)) +
geom_point(size = 0.5)
my_plot
mirror <- recordPlot()
png(filename = "mypath",
width = dev.size('px')[1]/96,
height = dev.size('px')[2]/96,
res = 96, # base RStudio resolution
units = "in",
type = "cairo") # calls CairoSVG
replayPlot(mirror)
dev.off()
(Note : I prefer the use of png() rather than ggsave() because it will save the entire last plot. I have observed that ggsave() would save only the last facet of a grid, for example)
Is it possible to remove the background of images with the magick package?
I know how to use edge detection with Gimp/Inkscape to crop out silhouettes; however, I'm looking to automate the process for a large batch of images with R.
My ultimate goal is to use the ggimage package to plot these images as x,y coordinates but the background of these images is currently overlapping the plot (the dog compared to fink)
library("ggplot2")
library("ggimage")
set.seed(2017-02-21)
d <- data.frame(x = rnorm(10),
y = rnorm(10),
image = sample(c("http://www.supercoloring.com/sites/default/files/silhouettes/2015/05/cairn-terrier-black-silhouette.svg", "https://jeroenooms.github.io/images/frink.png"),
size=10, replace = TRUE)
)
ggplot(d, aes(x, y)) + geom_image(aes(image=image))
One can trim the edges of an image using image magick's image_trim()
img <- image_read_svg("http://www.supercoloring.com/sites/default/files/silhouettes/2015/05/cairn-terrier-black-silhouette.svg")
image_trim(img)
but this isn't exactly what I would like.
Any ideas?
The image_transparent() function does this, e.g.:
logo <- image_read("logo:")
image_transparent(logo, 'white')
The white parts of the image will be made transparent, which should be enough for the simple image in your example.
see my answer in https://yulab-smu.github.io/treedata-book/image-processing-using-magick-package.html#example-1-remove-background-of-images.
You can pass image processing function provided by magick package to geom_image via the image_fun parameter.
I have a ggplot object. Let's call it plot. I would like to convert it to png format, but I don't want to save it to a file on my local drive. I'm trying to work with that png object but I want to keep everything in the environment. Everything I've found, including ggsave, appears to force one to save the image as a file on the local drive first. I know image files can be stored as values, but I can't seem to get over the "save as" image and "import" image steps.
Here's some code for repoducibility:
library(tidyverse)
df <- as.data.frame(Titanic)
gg <- ggplot(data = df, aes(x = Survived, y = Freq))
plot <- gg + geom_bar(stat = "identity")
Now, I'd like to convert plot to a png to png without having to save it to a file. Something like:
png <- save.png(plot)
Thanks for the help!
It looks like the goal here would be to convert plot (the ggplot object) directly to a Magick image that you can operate on with functions in the magick package. Something like this:
mplot = image_graph(width=400, height=500)
plot
dev.off()
image_graph opens a graphics device that produces a Magick image and assigns it to mplot so that you'll have the object available in your environment. Then, when you type mplot in the console, you'll see the following:
format width height colorspace matte filesize density
1 PNG 400 500 sRGB TRUE 0 +72x+72
However, when I try to display the mplot image (type mplot in the console), I see the following:
even though the original plot looks like this:
I'm not sure what's going wrong, but hopefully someone with greater familiarity with magick will drop by and provide a solution.
I was faced with a similar issue and followed #eipi12 approach of using magick. The code bellow should work:
library(ggplot2)
library(magrittr)
ggsave_to_variable <- function(p, width = 10, height = 10, dpi = 300){
pixel_width = (width * dpi) / 2.54
pixel_height = (height * dpi) / 2.54
img <- magick::image_graph(pixel_width, pixel_height, res = dpi)
on.exit(utils::capture.output({
grDevices::dev.off()}))
plot(p)
return(img)
}
p <- data.frame(x = 1:100, y = 1:100) %>%
ggplot(aes(x = x, y = y)) +
geom_line()
my_img <- ggsave_to_variable(p)
my_img %>%
magick::image_write("my_img.png")
I am fairly new to R/ggplot2 and still learning on the go. Hopefully I am not missing something obvious!
I am trying to create several different plots using ggplot2 that I am layouting using the function plot_grid from the cowplot package to make the plots visible side by side and add plot numeration and captions. The problem is that if the generated plots are displayed in a small window or I have many plots beside one another then the titles of the two plots sometimes overlap. To solve this problem I tried to automatically insert line breaks in my too long titles using code I found in another thread since I wanted the text size of the titles to stay constant.
Using the following code I can easily automatically insert the necessary line breaks to make my title a specific width, but the problem is that I always need to enter a numeric value for the width. Depending on the number of plots I am inserting this value would of course change. I could of course go through my code and manually set the width for each set of plots until it is the correct value, but I was hoping to automate this process so that the title width is adjusted automatically to match the width of the x-axis. Is there anyway to implement this in R?
#automatically line break and add titles
myplot_theme1 = function (plot, x.title = NULL, y.title = NULL, plot.title = NULL) {
plot +
labs(title = paste(strwrap(plot.title, width = 50), collapse = "\n"),
x = x.title,
y = y.title)
}
# generate an example plot
data_plot <- data.frame(x = rnorm(1000), y = rnorm (1000))
plot1 <- ggplot(data_plot, aes(x = x, y = y)) + geom_point()
title <- "This is a title that is very long and does not display nicely"
myplot_theme1(plot1, plot.title = title)
My test plot
I have tried searching but I haven't found any solutions that seem to address what I am looking for. The only solution I did find that looked promising was based on the package gridDebug. This packages doesn't seem to be supported by my operating system anymore though (macOS Sierra Version 10.12.6) since when I try to install it I get the following error message:
Warning in install.packages: dependencies ‘graph’, ‘Rgraphviz’ are not available
And on the CRAN package documentation it states that the package is not even available for macOS El Capitan which was my previous operating system. If someone knows what is causing this issue so that I could try the solution from the above thread that would of course be great as well.
One idea (but perhaps not an ideal solution) is to adjust the size of text based on the number of characters in the title. You can adjust ggplot properties using theme and in this case you want to adjust plot.title (the theme property, not your variable). plot.title has elements size and horizontal justification hjust, the latter is in range [0,1].
# generate an example plot
data_plot <- data.frame(x = rnorm(1000), y = rnorm (1000))
plot1 <- ggplot(data_plot, aes(x = x, y = y)) + geom_point()
title1 <- "This is a title that is very long and does not display nicely"
title2 <- "I'm an even longer sentence just test me out and see if I display the way you want or you'll be sorry"
myplot_theme1 = function (plot, x.title = NULL, y.title = NULL, plot.title = NULL) {
plot +
labs(title = plot.title,
x = x.title,
y = y.title) +
theme(plot.title = element_text(size=800/nchar(plot.title), hjust=0.5)) # 800 is arbitrarily chosen
}
myplot_theme1(plot1, plot.title = title1)
myplot_theme1(plot1, plot.title = title2)