course <- c ("Data Minig With R", "Matlab", "Java")
> Publish_date <- c ("Farvardin", "Shahrivar", "Aban")
> Cost <- c (18000, 20000, 19500)
> Faradars.Courses <- data.frame (course, Publish_date, Cost, stringsAsFactors = FALSE)
> str (Faradars.Courses)
'data.frame':   3 obs. of  3 variables:
 $ course      : chr  "Data Minig With R" "Matlab" "Java"
 $ Publish_date: chr  "Farvardin" "Shahrivar" "Aban"
 $ Cost        : num  18000 20000 19500
> Faradars.Courses
             course Publish_date  Cost
1 Data Minig With R    Farvardin 18000
2            Matlab    Shahrivar 20000
3              Java         Aban 19500
> Faradars.Courses$course
[1] "Data Minig With R" "Matlab"            "Java"             
> Faradars.Courses[1,2]
[1] "Farvardin"
> Faradars.Courses[1:2,]
             course Publish_date  Cost
1 Data Minig With R    Farvardin 18000
2            Matlab    Shahrivar 20000
> Faradars.Courses[,1]
[1] "Data Minig With R" "Matlab"            "Java"             
> Faradars.Courses <- rbind (Faradars.Courses, c("C++", "Bahman", 30000))
> Faradars.Courses
             course Publish_date  Cost
1 Data Minig With R    Farvardin 18000
2            Matlab    Shahrivar 20000
3              Java         Aban 19500
4               C++       Bahman 30000
> Faradars.Courses <- cbind (Faradars.Courses, Rank = c("A", "B", "A", "C"))
> Faradars.Courses
             course Publish_date  Cost Rank
1 Data Minig With R    Farvardin 18000    A
2            Matlab    Shahrivar 20000    B
3              Java         Aban 19500    A
4               C++       Bahman 30000    C
> dis <- c (5, 4, 7, 10)
> Faradars.Courses$Discount <- dis
> Faradars.Courses
             course Publish_date  Cost Rank Discount
1 Data Minig With R    Farvardin 18000    A        5
2            Matlab    Shahrivar 20000    B        4
3              Java         Aban 19500    A        7
4               C++       Bahman 30000    C       10
> Faradars.Courses$Rank <- Null
Error: object 'Null' not found
> Faradars.Courses$Rank <- NULL
> Faradars.Courses
             course Publish_date  Cost Discount
1 Data Minig With R    Farvardin 18000        5
2            Matlab    Shahrivar 20000        4
3              Java         Aban 19500        7
4               C++       Bahman 30000       10
> Faradars.Courses <- Faradars.Courses [-3,]
> Faradars.Courses
             course Publish_date  Cost Discount
1 Data Minig With R    Farvardin 18000        5
2            Matlab    Shahrivar 20000        4
4               C++       Bahman 30000       10
> txt <- read.table (file.choose())
> df <- data.frame (txt)
> df
                  V1        V2 V3
1        Programming     Shiny 98
2    Game_Develpment     Unity 98
3           DataBase     NoSQL 99
4    Web_Development Usability 99
5 Mobile_Development  PhoneGap 99
> write.table (Faradars.Courses, file = "FC.txt")
> tx <- read.table (file.choose())
> head(tx)
             course Publish_date  Cost Discount
1 Data Minig With R    Farvardin 18000        5
2            Matlab    Shahrivar 20000        4
4               C++       Bahman 30000       10
> View(Faradars.Courses)
> Faradars.Courses <- edit(Faradars.Courses)
> View(Faradars.Courses)
> 
