How to create a data frame with numeric and character columns?

Question

I'm trying to build a data frame consisting of three character variables and one numeric variable. When I run the following code, I get a four-column matrix, but the score variable is no longer numeric, and the scores are treated as factors.

school<-c("NYU", "BYU", "USC", "FIT", "UNH","UCLA","USF","Columbia")
state<-c("NY","UT","CA","NY","NY","CA", "CA","NY")
measure<-c("MSAT","MSAT","GPA","MSAT","MSAT","GPA","GPA","GPA")
score<-c(500, 490, 2.9, 759, 550, 1.2, 3.1, 3.2)
data<-cbind(school,state, measure,score)

If I run

data1<-data.frame(cbind(school,state, measure,score))

I get a data frame where score is still a factor. How can I build this data frame so that score is numeric?

Baranowski

If you want to create a data frame, use data.frame() directly, without cbind. – Frenulum

Answer 1

To build a data frame consisting of three character variables and one numeric variable, you need to specify: stringsAsFactors=FALSE in data.frame() function:

school<-c("NYU", "BYU", "USC")
state<-c("NY","UT","CA")
measure<-c("MSAT","MSAT","GPA")
score<-c(500, 490, 2.9)
df<-data.frame(school,state, measure,score,  stringsAsFactors=FALSE)

Here's the result:

summary(df)
school             state             measure              score      
Length:3           Length:3           Length:3           Min.   :  2.9  
Class :character   Class :character   Class :character   1st Qu.:246.4  
Mode  :character   Mode  :character   Mode  :character   Median :490.0  
                                                         Mean   :331.0  
                                                         3rd Qu.:495.0  
                                                         Max.   :500.0  

Judicious

Answer 2

 school<-c("NYU", "BYU", "USC", "FIT", "UNH","UCLA","USF","Columbia")
 state<-c("NY","UT","CA","NY","NY","CA", "CA","NY")
 measure<-c("MSAT","MSAT","GPA","MSAT","MSAT","GPA","GPA","GPA")
 score<-c(500, 490, 2.9, 759, 550, 1.2, 3.1, 3.2)
 data<-data.frame(school,state, measure,score)
 data
   school state measure score
     NYU    NY    MSAT 500.0
     BYU    UT    MSAT 490.0
     USC    CA     GPA   2.9
     FIT    NY    MSAT 759.0
     UNH    NY    MSAT 550.0
    UCLA    CA     GPA   1.2
     USF    CA     GPA   3.1
Columbia    NY     GPA   3.2

is.numeric(data$score)
[1] TRUE

I guess This should work !!!

Mimeograph

Almost working, stringsAsFactors is the only missing part (try str(data)) – Incise