calculate quantiles in R

calculate_quantiles.r

# launch R console from Mac Spotlight

# navigate to file directory
setwd("/Users/Tenorio/Desktop")

# load the file 'times.txt' in table format
counts <- read.table('times.txt')

# check if the file is read properly
# V1 is the default column name if no column title is specified
# head() will show the first 6 values imported
head(counts)


# calculate the default quantile values:
# 0%         25%         50%         75%        100% 
quantile(counts$V1)

# calculate custom quantile values:
#       25%       50%       95% 
quantile(counts$V1, c(.25, .5, .95))

# calculate custom quantile values to visualize outliers or extreme values
# p is the list of all values to check
p <- c(0.1, 0.2, 0.4, 0.6, 0.8, 1, 2, 4, 6, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 92, 94, 96, 98, 99, 99.2, 99.4, 99.6, 99.8, 99.9, 100)
q5 <- quantile(counts$V1,  probs = p/100)

# create the graph
plot(p,q5)

# to save quartz plot to pdf file:  File > Save > Dialog...