How big a fraction of wind directions fall into South-East direction

wind_SE.R

# Read in the data
dat <- read.csv("...", sep=";", header=T)
 
# Calculate the percentage values for each 10° category
# Divide each row n value with the sum of all n's
# Round to precision 3, this will cause a slight 
# rounding error
dat$percent <- round(dat$n / sum(dat$n) * 100, 3)
 
# Get just the South-East [90°, 180°]
dat.SE <- subset(dat, Wd_10min >= 90 & Wd_10min <= 180)
# Sum the percentages and print
perc.SE <- sum(dat.SE$percent)
perc.SE