R code that generates charts from Strava API (http://strava.github.io/api/v3/activities/)

strava-charts.r

library(rjson)
library(httr)
library(ggplot2)
library(scales)

if (interactive()) {
  token <- readline(prompt="Enter Strava access token: ")
  activities <- GET("https://www.strava.com/", path = "api/v3/activities",
                    query = list(access_token = token, per_page = 200))
  activities <- content(activities, "text")
  activities <- fromJSON(activities)
  activities <- lapply(activities, function(x) {
    x[sapply(x, is.null)] <- NA
    unlist(x)
  })
  df <- data.frame(do.call("rbind", activities))
  
  df$distance <- as.numeric(as.character(df$distance)) / 1000 # m -> km
  df$moving_time <- as.numeric(as.character(df$moving_time)) / 60 # s -> m
  df$start_date <- as.Date(df$start_date) # yyyy-mm-dd
  df$average_speed <- as.numeric(as.character(df$average_speed)) * 3.6 # m/s -> km/h
  
  ggplot(df, aes(x=distance, y=moving_time)) +
    geom_point(size=1, aes(colour = type)) +
    geom_smooth(method=lm, aes(colour = type)) +
    xlab("distance per activity (kilometers)") +
    ylab("moving time (minutes)")
  ggsave("/tmp/moving-time.png")
  
  ggplot(df, aes(x=start_date, y=average_speed)) + 
    geom_point(size=1, aes(colour = type)) +
    scale_x_date(labels = date_format("%Y-%m-%d")) +
    xlab("date") +
    ylab("average speed (kilometers per hour)")
  ggsave("/tmp/speed.png")
  
} else
  writeLines("Non interactive session, giving up")