R Mon

Set this flag to TRUE when you want to write out plots.

write.plot.enabled = F

library(data.table)
library(dplyr)
library(ggplot2)

Read AAVSO data from file

raw <- read.csv("AAVSO R Mon.csv", as.is=TRUE)

Transform raw data

r.mon <- raw %>%
  mutate(jd=JD-2400000, mag=as.numeric(Magnitude), band=as.factor(Band)) %>%
  select(jd, mag, band) %>%
  filter(band == "V" | band == "Vis.") %>%
  filter(!is.na(mag))

## Warning in eval(substitute(expr), envir, enclos): NAs introduced by
## coercion

Plot AAVSO light curve

# Limit plot to the last 25 years.
xlim <- c(max(r.mon$jd)-25*365,max(r.mon$jd))

# Limit plot of brightness.
ylim <- c(9.5,14.5)

p <- ggplot(data=r.mon) +
  geom_point(aes(jd,mag,color=band), alpha=0.5) +
  scale_color_manual(name="Band", values=c("green","grey50")) +
  scale_y_continuous(trans="reverse") +
  labs(title="R Mon AAVSO Light Curve", x="Julian Date - 2400000", y="Brightness [mag]") +
  coord_cartesian(ylim=ylim, xlim=xlim) +
  theme_bw()
p

if(write.plot.enabled) write.plot(p)

Appendix

write.plot <- function(p, name=NULL, width=1024, height=576, font.size=16) {
  title <- ifelse(!is.null(name), name, p$labels$title)
  if (is.null(title)) stop("Neither name nor title given")
  filename <- paste0(title, ".png")
  png(filename,width, height)
  print(p + theme_bw(base_size=font.size))
  dev.off()
}