Importing a csv file with math expressions into R, evaluating them into the results

math_csv_import.R

# To get from: 
# telecaster:data_collection_scripts fernandoipar$ cat /tmp/test.csv
# 1*1,0,1
# 1*2,0,2
# 2+4,1*1024*1024,2*1024*1024*1024
# to:
# > t
#   V1      V2         V3
# 1  1       0          1
# 2  2       0          2
# 3  6 1048576 2147483648


t <- read.csv("/tmp/test.csv",header=F,stringsAsFactors=F)

for (row in 1:nrow(t)) {
   for (col in 1:ncol(t)) {
       t[col,row] <- eval(parse(text=as.character(t[col,row])))
       }
}

# The problem here is that date/time fields will be interpreted as intervals, so if
# importing a csv with such fields (as is the case of my original goal here, to import
# mongostat output into R) this is needed: 

mongostat <- read.csv("/tmp/mongostat.csv",header=T,stringsAsFactors=F)

for (row in 1:nrow(mongostat)) {
   for (col in 1:ncol(mongostat)) {
       if (length(grep("[0-9][0-9]:[0-9][0-9]", mongostat[row,col])) == 0) {
           mongostat[row,col] <- eval(parse(text=as.character(mongostat[row,col])))
       }
   }
}