I already introduced some stuff I did with the last.fm API. But did you ever wonder if your taste of music changes over the year? Sunny music in the sunny months and dark music in darker months? Well, I did. And I want to check it out with the RLastFM package and some additional functions.

First, we load the package and assign an API key to the global variable api.key, you have to get yourself an API key to test this stuff.

library(RLastFM)
api.key <- <your key here>

I define a function which only calls another one from the RLastFM package. This isn't really necessary.


get.chart.list <- function (user, key = api.key) {
  user.getWeeklyChartList(user, key)
}

The following function changes a chart list to make intervals larger than weeks (in the beginning, this function only supplied months, hence the name).


make.months <- function (week.list, range = 4) {
  max.w <- nrow(week.list)
  start.weeks.i <- seq(1, max.w, range)
  end.weeks.i <- seq(range, max.w, range)
  if (length(start.weeks.i) > length(end.weeks.i)) {
    end.weeks.i <- c(end.weeks.i, max.w)
    cat("start weeks:", length(start.weeks.i), "\n", " end weeks:", length(end.weeks.i), "\n")
  }
  start.weeks <- week.list[start.weeks.i, "from"]
  end.weeks <- week.list[end.weeks.i, "to"]
  data.frame(from = start.weeks, to = end.weeks)
}


The next functions cleans a chart list. It removes all weeks no plays are recorded in.


clear.charts <- function (charts) {
  el.lens <- sapply(charts, FUN = function (x) {
    if (length(x) > 1) {
      length(x$artist)
    }
    else { NA }
  } )
  first.with.something <- which(el.lens > 0)[1]
  charts[first.with.something:length(charts)]
}


Now for the calls! Let's get the weekly charts for me ('swolf2008').


week.charts <- make.time.charts(user="swolf2008", range=1, wait.for.rec.sec=0)