Images as x-axis labels
Open-source software is awesome. If I found that a piece of closed-source software was missing a feature that I wanted, well, bad luck. I probably couldn't even tell if was actually missing or if I just didn't know about it. When the source is available, maintained, and documented however, things get fun. We can identify, and perhaps fill gaps.
I've thought for a couple of projects which had bar-graphs that it would be neat to have the categories labelled by an icon or a picture. Say, the logo for a company or an illustrative example. Sure, you could fire up GIMP/Inkscape and manually insert them over the top of the text labels (each and every time you re-produce the graph... no thanks) but that's not how I operate.
There are probably very few cases for which this is technically a good idea (trying to be a featured author on JunkCharts might very well be one of those reasons). Nonetheless, there are at least a couple of requests for this floating around on stackoverflow; here and here for example. I struggled to find any satisfactory solutions that were in current working order (though perhaps my Google-fu has failed me).
The second link there has a working example, but the big update to ggplot2
breaks that pretty strongly; opts
was deprecated and now element_text()
has a gatekeeper validation routine that prevents any such messing around. The first link however takes a different route. I couldn't get that one to work either, but in any case the answer is a year out of date (updates in ggplot2
can easily have broken the gTree
relations), not particularly flexible, and relies on saving intermittent image files for PostScriptTrace
to read back in which I'm not a fan of (and couldn't get to work anyway).
I decided that I perhaps had enough ammunition to hack something together myself (emphasis on hack), and sure enough it seems to have worked (for a limited definition of "worked" with no attached or implied guarantees whatsoever).
GDP per capita with flags for x-axis labels. This was harder to make than it seemed, but I've since added a little more flexibility to it.
The way to go about making your own is as follows;
- Stop and carefully re-evaluate the choices that you've made to bring you to this decision. Are you sure? Okay...
- Save the images (in the correct factor order) into a list (e.g.
pics
). - Build your bar graph with categorical x-axis as per normal, using
theme()
to remove the labels. Save as an object (e.g.g
). - Source the function from this gist (at your own risk... copy and paste if you prefer):
devtools:: source_gist ( "1d1bdb00a7b3910d62bf3eec8a77b4a7" ) |
#' Replace categorical x-axis labels with images | |
#' | |
#' Pipe a ggplot2 graph (with categorical x-axis) into this function with the argument of a list of | |
#' pictures (e.g. loaded via readImage) and it builds a new grob with the x-axis categories | |
#' now labelled by the images. Solves a problem that you perhaps shouldn't have. | |
#' | |
#' @author J. Carroll, \email{jono@@jcarroll.com.au} | |
#' @references \url{http://stackoverflow.com/questions/29939447/icons-as-x-axis-labels-in-r-ggplot2} | |
#' | |
#' @param g ggplot graph with categorical x axis | |
#' @param pics ordered list of pictures to place along x-axis | |
#' | |
#' @return NULL (called for the side-effect of producing a new grob with images for x-axis labels) | |
#' | |
#' @import grid | |
#' @import ggplot2 | |
#' | |
#' @export | |
#' | |
#' @example | |
#' \dontrun{ggplot(data, aes(x=factor(x),y=y)) + geom_point() %>% add_images_as_xlabels(pics)} | |
#' | |
add_images_as_xlabels <- function(g, pics) { | |
## ensure that the input is a ggplot | |
if(!inherits(g, "ggplot")) stop("Requires a valid ggplot to attach images to.") | |
## extract the components of the ggplot | |
gb <- ggplot_build(gg) | |
xpos <- gb$panel$ranges[[1]]$x.major | |
yrng <- gb$panel$ranges[[1]]$y.range | |
## ensure that the number of pictures to use for labels | |
## matches the number of x categories | |
if(length(xpos) != length(pics)) stop("Detected a different number of pictures to x categories") | |
## create a new grob of the images aligned to the x-axis | |
## at the categorical x positions | |
my_g <- do.call("grobTree", Map(rasterGrob, pics, x=xpos, y=0)) | |
## annotate the original ggplot with the new grob | |
gg <- gg + annotation_custom(my_g, | |
xmin = -Inf, | |
xmax = Inf, | |
ymax = yrng[1] + 0.25*(yrng[2]-yrng[1])/npoints, | |
ymin = yrng[1] - 0.50*(yrng[2]-yrng[1])/npoints) | |
## turn off clipping to allow plotting outside of the plot area | |
gg2 <- ggplotGrob(gg) | |
gg2$layout$clip[gg2$layout$name=="panel"] <- "off" | |
## produce the final, combined grob | |
grid.newpage() | |
grid.draw(gg2) | |
return(invisible(NULL)) | |
} |
- Call (or pipe your
ggplot
object to) the function:
g %>% add_images_as_xlabels (pics) ## or add_images_as_xlabels (g, pics) |
- Your image will be re-drawn with your pictures labelling the categories.
Here's an example of the code used to generate the GDP per capita image, featuring some fairly brief (for what it does) rvest
scraping (to reiterate; I don't want to have to do any of this by hand, so let's code it up!).
library(rvest) | |
## GDP per capita, top 10 countries | |
url <- "https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)_per_capita" | |
html <- read_html(url) | |
gdppc <- html_table(html_nodes(html, "table")[3])[[1]][1:10,] | |
## clean up; remove non-ASCII and perform type conversions | |
gdppc$Country <- gsub("Â ", "", gdppc$Country) | |
gdppc$Rank <- iconv(gdppc$Rank, "latin1", "ASCII", sub="") | |
gdppc$Country <- iconv(gdppc$Country, "latin1", "ASCII", sub="") | |
gdppc$`US$` <- as.integer(sub(",", "", gdppc$`US$`)) | |
## flag images (yes, this processing could be done neater, I'm sure) | |
## get the 200px versions | |
flags_img <- html_nodes(html_nodes(html, "table")[3][[1]], "img")[1:10] | |
flags_url <- paste0('http://', sub('[0-9]*px', '200px', sub('\\".*$', '', sub('^.*src=\\"//', '', flags_img)))) | |
flags_name <- sub('.*(Flag_of)', '\\1', flags_url) | |
if(!dir.exists("flags")) dir.create("flags") | |
for(flag in seq_along(flags_url)) { | |
switch(Sys.info()[['sysname']], | |
Windows= {download.file(flags_url[flag], destfile=file.path("flags", paste0(flag,"_", flags_name[flag])), method="auto", mode="wb")}, | |
Linux = {download.file(flags_url[flag], destfile=file.path("flags", paste0(flag,"_", flags_name[flag])))}, | |
Darwin = {print("Not tested on Mac. Use one of the above and find out?")}) | |
} | |
library(EBImage) ## readImage | |
library(dplyr) ## %>% | |
library(ggplot2) ## devtools::install_github("hadley/ggplot2) | |
library(grid) ## rasterGrob | |
library(ggthemes) ## theme_minimal | |
library(scales) ## comma | |
## create a dummy dataset | |
npoints <- length(flags_name) | |
y <- gdppc$`US$` | |
x <- seq(npoints) | |
dat <- data.frame(x=factor(x), y=y) | |
## load the images from filenames | |
## one day I'll remember to make these sorted on save | |
pics <- vector(mode="list", length=npoints) | |
image.file <- dir("flags", full.names=TRUE) | |
image.file <- image.file[order(as.integer(sub("_.*", "", sub("flags/", "", image.file))))] | |
## save the images into a list | |
for(i in 1:npoints) { | |
pics[[i]] <- EBImage::readImage(image.file[i]) | |
} | |
## create the graph, as per normal | |
## NB: #85bb65 is the color of money in the USA apparently. | |
gg <- ggplot(dat, aes(x=x, y=y/1e3L, group=1)) | |
gg <- gg + geom_bar(col="black", fill="#85bb65", stat="identity") | |
gg <- gg + scale_x_discrete() | |
gg <- gg + theme_minimal() | |
gg <- gg + theme(plot.margin = unit(c(0.5,0.5,5,0.5), "lines"), | |
axis.text.x = element_blank(), | |
axis.text.y = element_text(size=14)) | |
gg <- gg + scale_fill_discrete(guide=FALSE) | |
gg <- gg + theme(plot.background = element_rect(fill="grey90")) | |
gg <- gg + labs(title="GDP per Capita", subtitle=paste0("Top 10 countries\n(", url, ")"), x="", y="$US/1000") | |
gg | |
## insert imags (pics) as x-axis labels | |
## well, at least appear to do so | |
gg %>% add_images_as_xlabels(pics) |
At least a few caveats surround what I did manage to get working, including but not limited to:
- I'm not sure how to put the x-axis title back in at the right position without padding it with a lot of linebreaks (
"\n\n\n\nX-AXIS TITLE"
). - I'm not sure how to move the
caption
line fromlabs()
(assuming you're using the development version ofggplot2
on GitHub with @hrbrmstr's excellent annotation additions) so it potentially gets drawn over. - The spacing below the graph is currently arbitrarily set to a few lines more than necessary, but it's a compromise in having an arbitrary number of images loaded at their correct sizes.
- Similarly, I've just expanded the plot range of the original graph by a seemingly okay amount which has worked for the few examples I've tried.
- Using a graph like this places the onus of domain knowledge onto the reader; if you don't know what those flags refer to then this graph is less useful than one with the countries labelled with words. Prettier though.
I've no doubt that there must be a better way to do this, but it's beyond my understanding of how ggproto
works, and I can't seem to bypass element_text
's requirements with what I do know. If you would like to help develop this into something more robust then I'm most interested. Given that it's a single function I wasn't going to create a package just for this, but I'm willing to help incorporate it into someone's existing package. Hit the comments or ping me on Twitter (@carroll_jono)!
转自:http://jcarroll.com.au/2016/06/02/images-as-x-axis-labels/
Images as x-axis labels的更多相关文章
- Axis.Labels.CustomSize
tChart1.Axes.Bottom.Labels.CustomSize = ; //Changes spacing occupied by the axis labels between the ...
- 3D Slicer Hide 3D Cube and Axis Labels Programmatically 使用代码隐藏三维视图中的方框和坐标轴标签
在3D Slicer中,我们如果想在自己写的插件中来修改三维视图中的默认设置的话,那么首先就需要获得三维视图的结点,其类型为vtkMRMLViewNode,获得了这个结点后,我们就可以用代码来修改一系 ...
- TeeChart中Axis的CalcIncrement属性
private void Init() { tChart = new TChart(); panel1.Controls.Add(tChart); tChart.Aspect.View3D = fal ...
- 应用matplotlib绘制地图
#!/usr/bin/env python # -*- coding: utf-8 -*- from math import sqrt import shapefile from matplotlib ...
- 数字格式化函数:Highcharts.numberFormat()
(转)数字格式化函数:Highcharts.numberFormat() 一.函数说明 该函数用于图表中数值的格式化,常见用途有数值精度控制.小数点符.千位符显示控制等. 二.函数使用 1.函 ...
- Highcharts X轴名称太长,如何设置下面这种样式
Highcharts所有的图表除了饼图都有X轴和Y轴,默认情况下,x轴显示在图表的底部,y轴显示在左侧(多个y轴时可以是显示在左右两侧),通过chart.inverted = true 可以让x, ...
- R绘图基础
一,布局 R绘图所占的区域,被分成两大部分,一是外围边距,一是绘图区域. 外围边距可使用par()函数中的oma来进行设置.比如oma=c(4,3,2,1),就是指外围边距分别为下边距:4行,左边距3 ...
- Python图表绘制:matplotlib绘图库入门
matplotlib 是Python最著名的绘图库,它提供了一整套和matlab相似的命令API,十分适合交互式地行制图.而且也可以方便地将它作为绘图控件,嵌入GUI应用程序中. 它的文档相当完备,并 ...
- (转)数字格式化函数:Highcharts.numberFormat()
一.函数说明 该函数用于图表中数值的格式化,常见用途有数值精度控制.小数点符.千位符显示控制等. 二.函数使用 1.函数构造及参数 Highcharts.numberFormat (Numbe ...
- 数据可视化(5)--jqplot经典实例
本来想把实例也写到上篇博客里,最后发现太长了,拆成两篇博客了. 实例来源于官方文档:http://www.jqplot.com/tests/ 这篇博客主要是翻译了官方文档关于经典实例的解说,并在相应代 ...
随机推荐
- Java中集合框架,Collection接口、Set接口、List接口、Map接口,已经常用的它们的实现类,简单的JDK源码分析底层实现
(一)集合框架: Java语言的设计者对常用的数据结构和算法做了一些规范(接口)和实现(实现接口的类).所有抽象出来的数据结构和操作(算法)统称为集合框架. 程序员在具体应用的时候,不必考虑数据结构和 ...
- linux里的那么点东西(持续更新)
作为一个程序猿的确是应该上的了windows,下的了linux的.但是由于没有对linux产生一些刚性的需求,所以使用的次数还是略少,对一些基本的concept和command还是有一些生疏.借着最近 ...
- c#控制台实现post网站登录
如题,首先我写了一个web页面来实现post登陆,只做演示,代码如下 public void ProcessRequest(HttpContext context) { context.Respons ...
- STM32学习笔记(二)——串口控制LED
开发板芯片:STM32F407ZGT6 PA9-USART1_TX,PA10-USART1_RX; PF9-LED0,PF10-LED1; 一.串口1配置过程(不使用串口中断): 1.使能时钟,包括G ...
- 【linux 爱好者群】程序猿的那些聊天记录
分享&&交流&&开放 you should get it 声明:好吧,我们的群只有5个人,但是有句话不是说的很对吗,一个项目最理想的不就是5个人么.我是写文本那个. 下 ...
- Node.js系列:Buffer类的使用
客户端JavaScript中没有对二进制数据提供很好的支持.但是在处理TCP流或文件流时,必须要处理二进制数据.Node.js定义了一个Buffer类,用来创建一个专门存放二进制数据的缓存区. Buf ...
- Java 比较(==, equals, compareTo, compare)
在Java中,有 ==, equals(), compareTo(), compare() 等方法可以比较两个值或对象,比较容易混淆.画了个简单的思维导图总结一下 Java Compares 我经常记 ...
- golang kafka
golang kafka – hello world https://github.com/Shopify/sarama https://shopify.github.io/sarama/ con ...
- Filter和Listener的应用——分IP统计网站访问次数
一:分析 统计工作需要在所有资源执行前进行,所以需要放在filter中 这个拦截器仅仅进行统计工作,不进行拦截,所以请求必须继续传递下去 用Map<String,integer>来保存数据 ...
- Xamarin.Android 绑定友盟社会化分享组件
Xamarin.Android 绑定友盟社会化分享组件 最近在开发博客园Android App的时候需要用到友盟社会化分享组件,在github上搜了一下都没有找到最新版本绑定好的项目,就自己动手来绑定 ...