Question

I have my data in a space-separated text file; each line represents a data point contained in a given month:

Jan/2012 1000
Jan/2012 1500
Jan/2012 1200
Feb/2012 1300
Feb/2012 1400
Feb/2012 1000
...
Dec/2012 1300
Dec/2012 1400
Dec/2012 1000

I’d like to generate for each month the min, max, median, mean, standard deviation, and 95th quantile. I’d also like to generate a boxplot for the entire year. How can I do this in R? I can load the data with mydata = read.table(file="mydata.txt", sep=" "), but summary produces output like:

      month              time          
 Aug/2012: 229357   Min.   :    31100  
 Oct/2012: 223158   1st Qu.:    91267  
 Mar/2012: 221986   Median :   124048  
 Apr/2012: 215368   Mean   :   199639  
 Jul/2012: 213956   3rd Qu.:   176766  
 May/2012: 200920   Max.   :150018802  
 (Other) :1146616                      

I don’t have any experience generating boxplots; guidance is welcome.

Answer 1

tapply(dfrm$time, substr(dfrm$month, 1,3), summary)
library(Hmisc)
tapply(dfrm$time, substr(dfrm$month, 1,3), describe)
boxplot(time~month, data=dfrm)