CODEWITHSUNDEEP
rvector
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Reputation: 57176

R - how to concat a vector into a string?

I have this data for instance,

>rows
  ID  NAME AGE    ADDRESS SALARY
1  1  Paul  32 California  20000
2  2 Allen  25      Texas  15000
3  3 Teddy  23     Norway  20000
4  4  Mark  25 Rich-Mond   65000
5  5 David  27      Texas  85000
6  6   Kim  22 South-Hall  45000

and to get the data in the name columns only,

> rows[2]
   NAME
1  Paul
2 Allen
3 Teddy
4  Mark
5 David
6   Kim

And I want to join them into a string,

> paste(rows[2],collapse=" ")

result,

[1] c("Paul", "Allen", "Teddy", "Mark", "David", "Kim")

But this is what I am after,

Paul Allen Teddy Mark David Kim

Is it possible?

The entire code,

# Load package.
library("RSQLite")

# Load package.
library("sqldf")

# Load package.
library("tcltk")

# Connect to the sqlite file.
# Localhost.
DB <- dbConnect(SQLite(), dbname = "C:/../sqldf/testDB.sqlite3")

# Fetch all records in the table.
users <- dbGetQuery(
    DB,
    "SELECT *
    FROM users"
)

# SQL statements can be run by using the sql methods provided by sqlContext
rows <- sqldf("SELECT * FROM users")

png(filename="temp.png", width=500, height=500)

plot(1, 1, col = "white")
text(1, 1, paste(rows[2], collapse = ' '))

dev.off()

Upvotes: 3

Views: 97

Answers (1)

akrun
akrun

Reputation: 886938

We can use either

paste(rows[,2], collapse=' ')

Or

paste(rows[[2]], collapse=' ')

Or as @Frank mentioned, we can extract by the name of the column using either $ 

paste(rows$NAME, collapse=' ')

Or [[

paste(rows[['NAME']], collapse=' ')

as all of the above are extracting the columns as vector while rows[2] is still a data.frame. We can check the difference using str i.e. str(rows[2]) and str(rows[[2]]). For more info, we can look at ?Extract or ?'['

Upvotes: 5

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