R read.table与read.csv

Question

grades <- read.table("studentgrades.csv",header = TRUE,row.names="StudentID", sep = ",")

gradess <- read.csv("studentgrades.csv",header = TRUE,row.names="StudentID", sep = ",")

The result of read.table is:

grades
[1] First          Last           Math           Science        Social.Studies
<0 rows> (or 0-length row.names)

The result of read.csv is:

gradess
   First       Last Math Science Social.Studies
11   Bob      Smith   90      80             67
12  Jane      Weary   75      NA             80
10   Dan "Thornton"   65      75             70
40  Mary    O'Leary   90      95             92

I just don't know why the read.tables can not give me the right result.

Answer 1

The problem is due to the quote (') in O'Leary of last name column. You will need to change the default quote option in read.table which is set to the (') by default to get desired result.

If you use quote=NULL in read.table like below

grades <- read.table("studentgrades.csv",header = TRUE,sep=",",quote=NULL,row.names="StudentID")

Then you get the desired result.

> grades
    First        Last Math  Science Social.Studies
11    Bob       Smith   90       80             67
12   Jane       Weary   75       NA             80
10    Dan  "Thornton"   65       75             70
40   Mary     O'Leary   90       95             92