Using Ggplot2 to plot last.fm top 100 albums
This article is originally published at http://rpsychologist.com/
I found out that last.fm had made data files available for their Best of 2011 artist list, and I thought it’d be a great opportunity to learn some more about data management in R and Ggplot2.
I began by downloading and importing the
tab separated data file from last.fm (TSV).
# read data lastfm <- read.delim("~/Downloads/bestof_2011_tsv/bestof_2011_releases.tsv")
Then I did some data cleanup, because one row just contained junk and some columns were unnecessary. I also removed all entries after row 100.
# remove row 541 'cause it's just junk lastfm <- lastfm[-541,] # remove unnecessary columns lastfm <- lastfm[-c(3, 5)] # remove all rows after 100 lastfm <- lastfm[-c(101:nrow(lastfm)) , ]
I did a search for missing values, but none were found.
which(lastfm == "NULL", arr.ind = TRUE) which(is.na(lastfm), arr.ind = TRUE)
The XML-file contained information about artists location. So I loaded
it and cleaned it up a bit. The location column was a bit messy so I
edited manually in statas data editor, I figured it was the easiest
way. I then read the edited data file back into R and combined that
data.frame with the rest of the data from the TSV-file.
library(XML) last.xml <- xmlToDataFrame("~/Downloads/bestof_2011_xml/bestof_2011_releases.xml") last.xml <- last.xml[-c(101:nrow(last.xml)) , ] last.xml <- last.xml[-c(1,4,5,6,7,8,9)] write.dta(last.xml, "stata", version = 7L) # read stata-file library(foreign) last.xml <- read.dta(file="/Users/Kris/stata.dta") # combine data.frames lastfm <- cbind(lastfm, location = last.xml$location)
I tried plotting this
data.frame with ggplot but the location
variable contained 17 countries, which made a messy plot. Therefore I
choose to group some countries under the label "other".
lastfm$location <- as.character(lastfm$location) lastfm$location[lastfm$location %in% c("Denmark", "Sweden")] <- "Sweden/Denmark" lastfm$location[lastfm$location %in% c("Germany", "France","Paris","Australia", "New Zealand", "Iceland","Brazil", "Scotland", "Democratic Republic of the Congo", "Romania","Belgium", "Netherlands")] <- "Other"
I still wasn't satisfied with the plot, because it wasn't sorted after
album plays. I tried quite a lot of different methods of sorting the
data.frame before figuring out how to do it successfully with
lastfm$artist.name <- reorder(lastfm$artist.name, rowSums(lastfm))
I wanted my plot to have readable decimal notation so I created my own x-breaks.
library(scales) x.breaks <- cbreaks( c(0, max(lastfm$album.plays)), #range: 0 to album.plays max pretty_breaks(10), # 10 ticks labels = comma_format()) # create labels with commas, ie 10,000.
I also used my own custom colors for the plots legend, which I saved in
a list before initiating
location.color <- c("Canada" = "#7b8dbf", "Other" = "#f97850", "Sweden/Denmark" = "#df72b6", "UK" = "#57b894", "USA" = "#4a4a4a" ) )
Then, at last, I drew the plot with
library(ggplot2) ggplot(lastfm, aes(artist.name,album.plays, fill=location)) + geom_bar(stat="identity") + coord_flip() + # flip x and y xlab("Album Artist") + ylab("Album plays") + # Use the labels and breaks I defined earlier scale_y_continuous(breaks = x.breaks$breaks, labels = x.breaks$labels) + # Add a plot title opts(title = "Last.fm top 100 albums 2011", # Move the legend inside the plot to save space. legend.position=c(.85, .5), # Change it's background to white. legend.background=theme_rect(fill="#ffffff")) + # Use my custom color scale which I defined earlier. scale_fill_manual("Artist homeland", values = location.color)
We can see that the plot is dominated by USA and UK and that Adele and
Lady Gaga got exponentially more album plays than the rest. To give a
$location I used
Which gave the following:
Canada Other Sweden/Denmark UK USA 5 13 4 24 54
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